Clinical Topic A-Z Clinical Speciality

Mastitis and breast abscess

Mastitis and breast abscess
D008413Mastitis
D001942Breast Feeding
D007774Lactation
Infections and infestationsWomen's health
2010-05-17Last revised in May 2010

Mastitis and breast abscess - Summary

Lactation mastitis (puerperal mastitis) is an inflammatory condition of the interlobular connective tissue of the breast that affects up to 10% of breastfeeding women within the first 12 weeks of giving birth. The primary cause is milk stasis caused by overproduction or insufficient removal and may present as:

Non-infectious: occurs when accumulated milk causes an inflammatory response.

Infectious: usually an infection of commensal flora occurs by retrograde spread through a lactiferous duct or a traumatized nipple. Very rarely, the infection occurs through the lymphatics or by haematogenous spread.

Subclinical: associated with inadequate milk removal and poor infant weight gain.

Symptoms of mastitis include a painful breast; fever and general malaise; and a tender, red, swollen and hard area of the breast, usually in a wedge-shaped distribution. Mastitis may be infectious if symptoms do not improve or are worsening after 12–24 hours despite effective milk removal, the woman has a nipple fissure that is infected, or bacterial culture is positive.

First-line management includes:

Reassurance that although mastitis is a painful condition, the breast will return to normal size, shape, and function.

Antibiotics if infectious mastitis is suspected. Flucloxacillin is the antibiotic of choice for empirical treatment.

Paracetamol or ibuprofen to relieve pain and discomfort.

Topical treatment of nipple damage

Women with mastitis should be encouraged to continue breastfeeding. If this is not possible, expression of breast milk by by hand or using a breast pump is advised.

Referral is necessary if:

An underlying mass, ductal cancer, or inflammatory breast cancer (a rapid onset of warmth of the breast, diffuse redness varying from a faint blush to bright red, and oedema causing an 'orange skin' appearance) is suspected — arrange urgent investigation or referral.

An abscess is suspected — refer to a general surgeon.

A breast abscess is a localized collection of pus within the breast that occurs in around 3% of women, secondary to mastitis that has not been effectively managed. Complications of breast abscess include: early weaning, inability to breastfeed in the future, and the ned for resection.

A breast abscess should be suspected if the woman has:

A history of recent mastitis.

A painful, swollen lump in the breast with redness, heat, and swelling of the overlying skin.

Fever and malaise.

Any woman with a suspected breast abscess should be referred urgently to a general surgeon for confirmation of the diagnosis (by ultrasound), and for drainage of the abscess (by ultrasound-guided needle aspiration or surgical drainage).

Have I got the right topic?

120months3060monthsFemale

This CKS topic is based on the World Health Organization guideline, Mastitis — causes and management [WHO, 2000].

This CKS topic covers the diagnosis and management of mastitis (non-infectious and infectious) and breast abscess. The diagnosis and management of conditions that predispose to mastitis and breast abscess (including full breasts, engorged breasts, and blocked ducts) are covered in the CKS topic on Breastfeeding problems.

This CKS topic does not cover the secondary care management of breast abscess, or the management of infections of the breast in women who are not breastfeeding.

There are separate CKS topics on Breast cancer - managing FH, Breast cancer - suspected, Breast pain - cyclical, and Breast screening.

The target audience for this CKS topic is healthcare professionals working within the NHS in the UK, and providing first contact or primary health care.

How up-to-date is this topic?

How up-to-date is this topic?

Changes

Last revised in May 2010

February 2013 — minor update. The 2013 QIPP options for local implementation have been added to this topic [NICE, 2013].

October 2012 — minor update. The 2012 QIPP options for local implementation have been added to this topic [NPC, 2012].

May 2011 — minor update. The 2010/2011 QIPP options for local implementation have been added to this topic [NPC, 2011]. Issued in June 2011.

January 2011 — updated. Advice regarding infant attachment and the management of full breast, breast engorgement, nipple problems, or a blocked duct is now covered in the separate CKS topic on Breastfeeding problems.

February to May 2010 — this is a new CKS topic. The evidence-base has been reviewed in detail, and recommendations are clearly justified and transparently linked to the supporting evidence.

Update

New evidence

Evidence-based guidelines

No new evidence-based guidelines since 1 December 2009.

HTAs (Health Technology Assessments)

No new HTAs since 1 December 2009.

Economic appraisals

No new economic appraisals relevant to England since 1 December 2009.

Systematic reviews and meta-analyses

Systematic reviews published since the last revision of this topic:

Crepinsek, M.A., Crowe, L., Michener, K., and Smart, N.A. (2010) Interventions for preventing mastitis after childbirth (Cochrane Review). The Cochrane Library. Issue 8. John Wiley & Sons, Ltd. www.thecochranelibrary.com [Free Full-text]

Primary evidence

No new randomized controlled trials published in the major journals since 1 December 2009.

New policies

No new national policies or guidelines since 1 December 2009.

New safety alerts

No new safety alerts since 1 December 2009.

Changes in product availability

No changes in product availability since 1 December 2009.

Goals and outcome measures

Goals

To recognize mastitis and breast abscess promptly

To begin appropriate treatment of mastitis in primary care

To refer a woman with mastitis to secondary care or other specialist services, when appropriate

To refer a woman with a suspected breast abscess urgently to secondary care

QIPP — Options for local implementation

QIPP — Options for local implementation

Antibiotic prescribing — especially quinolones and cephalosporins

Review and, where appropriate, revise current prescribing practice and use implementation techniques to ensure prescribing is in line with Health Protection Agency (HPA) guidance.

Review the total volume of antibiotic prescribing against local and national data.

Review the use of quinolones and cephalosporin prescribing against local and national data.

[NICE, 2013]

Background information

Definition

What is it?

Lactation mastitis (puerperal mastitis) is an inflammatory condition of the breast which may or may not be associated with infection [WHO, 2000]. Inflammation occurs in the interlobular connective tissue [National Collaborating Centre for Primary Care, 2006].

Non-infectious mastitis occurs when accumulated milk causes an inflammatory response [WHO, 2000].

Infectious mastitis occurs when inadequate milk removal allows bacterial growth. Usually, infection occurs by retrograde spread through a lactiferous duct or a traumatized nipple. Very rarely, the infection occurs through the lymphatics or by haematogenous spread [Fetherston, 2001].

Subclinical mastitis is associated with reduced milk output. There is no breast tenderness. It is associated with inadequate milk removal and poor infant weight gain. If the woman is HIV positive, subclinical mastitis is associated with an increased HIV load in the milk which facilitates mother-to-child HIV transmission [WHO, 2000; Michie et al, 2003].

The boundaries between a full breast, engorged breast, blocked duct, non-infectious mastitis, and infected mastitis are indistinct.

Breast abscess is a localized collection of pus within the breast [WHO, 2000].

Causes

What causes it?

Milk stasis is the primary cause of mastitis. This occurs:

When the milk is not adequately removed from the breast.

Due to overproduction of milk (such as when the milk 'comes in' soon after delivery, predisposing to engorgement of the breasts).

Infection may accompany milk stasis and cause infectious mastitis.

The commonest organisms associated with infectious mastitis are Staphylococcus aureus and Staphylococcus albus.

Meticillin-resistant S. aureus (MRSA) infection is more common after Caesarean birth, or if antibiotics have been required (for example during labour or soon after a birth following in vitro fertilization).

Other organisms that have been implicated include:

Escherichia coli and streptococci (alpha and beta haemolytic and non-haemolytic) — which cause a few infections in the UK.

Candida and cryptococcus — which occasionally cause fungal mastitis.

Tuberculosis and salmonella; including Salmonella typhi (all very rare).

Breast abscess usually occurs secondary to mastitis that has not been effectively managed .

[Thomsen et al, 1984; Osterman and Rahm, 2000; WHO, 2000; WHO, 2009]

Prevalence

How common is it?

Most women who develop mastitis do so within the first 12 weeks post-partum (this accounts for 74–95% of women with mastitis), most commonly during the second or third week [WHO, 2000].

Mastitis affects up to 10% of breastfeeding women.

The World Health Organization (WHO) reviewed prospective cohort studies, retrospective analyses of medical records, retrospective questionnaires, and self-reported questionnaires; all were carried out between 1945 and 1996 and examined the prevalence of mastitis in breastfeeding women. WHO concluded that the incidence of mastitis is usually less than 10% [WHO, 2000].

A subsequent prospective cohort study in Michigan and Nebraska followed 946 breastfeeding women for a maximum of 12 weeks post-partum or until they ceased breastfeeding (if earlier). Diagnosis was made by telephone interview. At least one episode of mastitis (diagnosed by the participant's usual physician) was reported by 9.5% of women during the 12-week period [Foxman et al, 2002].

Around 3% of woman with mastitis develop a breast abscess.

A study (combined results of a randomized controlled trial and a survey) of 171 women treated with antibiotics for mastitis found that 3% developed a breast abscess [Amir et al, 2004].

Predisposing factors

What are the predisposing factors

Predisposing factors for milk stasis in women are:

Poor attachment [WHO, 2009] which leads to:

Inefficient milk removal.

Nipple pain, which may lead to avoidance of feeding on that side, resulting in engorgement and milk stasis [WHO, 2000; Spencer, 2008].

A restricted infant feeding schedule, leading to a reduction in the number and duration of feeds. This includes:

Having a preferred breast for feeding: stasis is more likely to develop in the other breast [WHO, 2000].

Long intervals between feeds or missed feeds (commonly, when the infant first starts to sleep through the night) [Spencer, 2008].

Rapid weaning [Academy of Breastfeeding Medicine, 2008].

Pressure on the breast, for example from sleeping in a prone position, tight clothing (including a tight bra), or a car seat belt [WHO, 2000; Amir, 2003; Spencer, 2008].

Trauma which may damage duct and gland tissue, such as from domestic violence.

Previous mastitis: this association is thought to be because of uncorrected poor breastfeeding technique [Spencer, 2008].

Predisposing factors for milk stasis in infants are:

Use of a dummy or bottle (as this may result in poor attachment at the breast and a reduction in the frequency and duration of breastfeeding). This can lead to engorgement and predispose to milk stasis [WHO, 2000].

Tongue-tie, which may prevent the infant removing milk effectively (the infant is not able to draw the full areola into its mouth, making breastfeeding difficult) [Mass, 2004; Spencer, 2008].

There is no evidence that breast size is related to the incidence of mastitis [WHO, 2000].

Why is effective attachment important?

Why is effective attachment important?

'It is likely that almost all postnatal breastfeeding problems could be prevented if an infant is able to breastfeed effectively and efficiently from the outset' [National Collaborating Centre for Primary Care, 2006].

Effective removal of milk by effective attachment and unrestricted breastfeeding are essential for good milk transfer. Milk stasis is a primary cause of both non-infective and infective mastitis [WHO, 2000].

Effective attachment of the infant to the breast is important to [WHO, 2009]:

Stimulate breast milk production.

Ensure effective milk transfer.

Ensure the supply of milk matches the infant's needs.

Protect the nipples from damage.

Help to prevent problems such as mastitis and blocked duct.

If attachment is poor then there may be:

Reduced milk transfer.

Insufficient milk to match the infant's needs.

Nipple soreness [National Collaborating Centre for Primary Care, 2006]. Sore nipples are a leading cause of discontinuation of breastfeeding [Anderson, 2009].

Prognosis

What is the prognosis?

With adequate treatment, recovery is usually prompt and dramatic. A complete recovery is expected, with a return to full lactation.

If treatment is delayed, inadequate, or inappropriate, or poor breastfeeding technique remains uncorrected, there may be a recurrence of more severe mastitis and permanent tissue damage [WHO, 2000; Academy of Breastfeeding Medicine, 2008].

The World Health Organization [WHO, 2000] reviewed available evidence and found that:

Women with mastitis often had a recurrence of the condition. Over half of women with mastitis had experienced at least one previous episode.

Recurrent mastitis may lead to chronic inflammation and disfigurement of the breast.

Future lactation is affected in about 10% of women with breast abscess.

Extensive resection of breast tissue because of a large abscess may cause disfigurement of the breast.

Complications

What are the complications?

Breast abscess (complication of mastitis).

A study (combined results of a randomized controlled trial and a survey) of 171 women treated with antibiotics for mastitis found that 3% developed a breast abscess [Amir et al, 2004].

Emotional distress due to unplanned early weaning of infant.

If the woman stops breastfeeding before she had planned to, she may experience a considerable amount of emotional distress [WHO, 2000].

Inability to breastfeed in the future.

Effective lactation is impossible in 10% of women who have had a breast abscess. A large abscess may need extensive resection and this may cause disfigurement and a functional mastectomy [WHO, 2000].

Vertical transmission of HIV/AIDS.

A prospective study of 334 lactating women with HIV-1 in Malawi found that mastitis increased the milk viral load 10-fold [Semba et al, 1999].

In the UK, this should not be an issue as women with HIV are advised not to breastfeed.

However, in developing countries there may be no alternative to breastfeeding. Women may also provide alternative milk feeds for the infant which facilitate transmission of HIV, as mixed feeding increases intestinal permeability [Michie et al, 2003].

Diagnosis

Diagnosis of mastitis

Diagnosis of mastitis

How do I know my patient has mastitis?

Clinical features of mastitis include:

A painful breast.

Fever.

General malaise.

A tender, red, swollen and hard area of the breast, usually in a wedge-shaped distribution.

It is not possible to distinguish clinically between non-infectious mastitis and infectious mastitis. Suspect infectious mastitis if:

Symptoms do not improve or are worsening after 12–24 hours despite effective milk removal.

The woman has a nipple fissure that is infected.

Bacterial culture is positive (For information on when to arrange culture of the breast milk, see Investigations).

Basis for recommendation

Basis for recommendation

Clinical features of non-infectious mastitis and infectious mastitis

These clinical features are based on expert opinion form a review of the causes and management of mastitis published by World Health Organization [WHO, 2000] and review articles [Barbosa-Cesnik et al, 2003; Betzold, 2007].

Distinguishing between non-infectious mastitis and infectious mastitis

Features to distinguish between infectious and non-infectious mastitis have been extrapolated from the criteria that the World Health Organization advises for starting an antibiotic [WHO, 2000; WHO, 2009]. As it is impossible to reliably distinguish clinically between infectious mastitis and non-infectious mastitis, CKS suggests that if these features are present an infectious cause is more likely and antibiotic treatment appropriate.

Expert opinion in Guidelines on the treatment, management & prevention of mastitis for Northern Ireland published by the Guidelines and Audit Implementation Network is that flu-like symptoms and pyrexia are more likely to last for longer than 24 hours in women with infectious mastitis compared with non-infectious mastitis, and women are likely to experience considerable breast discomfort in infectious mastitis [GAIN, 2009].

Diagnosis of breast abscess

How do I know my patient has a breast abscess?

Suspect a breast abscess if the woman has:

A history of recent mastitis.

A painful, swollen lump in the breast with redness, heat, and swelling of the overlying skin.

Fever and malaise (may have subsided if the woman has taken antibiotics).

On examination, the lump may be fluctuant with skin discolouration.

To confirm the diagnosis, refer the woman urgently to a general surgeon.

Basis for recommendation

Basis for recommendation

Clinical features

These clinical features are based on expert opinion from a review of the causes and management of mastitis published by the World Health Organization [WHO, 2000].

Confirmation of diagnosis

This recommendation is based on expert opinion in narrative reviews [Mass, 2004; Betzold, 2007; Spencer, 2008].

Investigations

Should I arrange any investigation ?

For a woman with a suspected breast abscess:

Refer urgently to a general surgeon for confirmation of the diagnosis by ultrasound, drainage of the abscess, and culture of fluid from the abscess.

For a woman with mastitis:

Investigations are not routinely required.

Culture the breast milk when:

Antibiotics have been prescribed and there has been no response after 48 hours.

Mastitis is severe before any antibiotics are prescribed.

The woman has recurrent mastitis.

Hospital-acquired infection is likely.

The woman is unable to take standard antibiotics (such as flucloxacillin and erythromycin).

There is severe deep 'burning' breast pain (indicative of ductal infection).

To collect a sample of breast milk into a sterile container:

Clean the nipple of the affected breast.

Express a small amount of milk by hand and discard it (to avoid skin contamination).

Express milk into a sterile container, avoiding touching the inside of the container with the nipple or hands.

Send the sample to the laboratory for microscopy, culture, and antibiotic sensitivity as soon as possible.

Basis for recommendation

Basis for recommendation

Referral for women with suspected breast abscess

This recommendation is based on expert opinion in narrative reviews [Mass, 2004; Betzold, 2007; Spencer, 2008].

Investigations are not routinely required for women with mastitis

The presence of bacteria in the milk does not necessarily indicate infection [WHO, 2000].

Bacterial counts are not reliable, because [Betzold, 2007]:

Milk from non-infected areas of the breast may dilute the pathogen.

Adequate milk flow may flush out the pathogen.

The flow of milk from the infected area may be obstructed.

The antibacterial properties of human milk may destroy bacteria.

Recommendations for when breast milk should be cultured

These recommendations are based on expert advice from the World Health Organization [WHO, 2000], the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008], and a narrative review [Betzold, 2007].

Collecting a sample of breast milk

This recommendation is based on expert advice from the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] and a narrative review [Spencer, 2008].

Differential diagnosis

What else might it be?

Conditions that cause pain and discomfort of the breast that are associated with lactation

Full breast.

Full breasts are common between the second and sixth day after birth.

Both breasts are usually affected.

Milk flows well and sometimes leaks spontaneously.

The infant finds it easy to attach and suckle.

The breasts feel hot, heavy, and hard.

The breasts are not shiny, oedematous or red.

Engorged breast.

This either occurs in the first few days after an infant is born when the breasts overfill with milk (primary engorgement), or occurs when feeding is less frequent or the infant's demands have decreased (secondary engorgement). It is also common after augmentation mammoplasty.

The breasts are enlarged, swollen, and painful.

It is usually bilateral.

The breasts may be shiny and there may be oedema with diffuse red areas.

The nipples may be stretched so that it is flat.

The milk does not flow easily.

The infant may find it difficult to attach and suckle.

The woman may have a fever that usually settles within 24 hours.

If untreated, lactation will be inhibited.

Breast engorgement occurs more commonly in women who have had augmentation mammoplasty.

A blocked duct.

There is a painful lump in the breast.

The woman has no fever.

The skin may be red over the lump.

A related condition is the appearance of a small (1 mm in diameter) white spot at the end of the nipple that is extremely painful when suckling; it is thought to be due to an overgrowth of epithelium (which forms a blister), or an accumulation of fatty or particulate material.

Galactocoele. Typically:

There is a smooth rounded, painless, swelling in the breast.

Milky fluid is discharged from the nipple when pressed.

Systemic symptoms are absent.

Infection of the mammary ducts (ductal infection is considered by some experts to be a cause of deep breast pain, but other experts dispute its existence).

There is a deep burning, aching, or shooting pain in the breast that is worse during or just after breastfeeding — this may be agonizing. There may be accompanying pain down the arm or in the back.

The woman does not have fever or malaise.

Clinical signs are variable and there may be: no redness, induration, or tenderness (that is, no clinical signs in the areola or nipple); pinkness or redness, flaking, shininess, or fissure of the nipple; purulent exudate or honey-coloured crusts suggesting bacterial infection.

Conditions that cause nipple pain

Poor attachment. This is the commonest cause of nipple pain and is usually present from the start of a breastfeed.

Candidal infection of the nipple. This often follows antibiotic treatment, but may also be a predisposing factor for mastitis. Clinical features include:

A burning sensation in the breast, intense itching, or severe nipple pain during and just after feeds. The pain may last up to 1 hour after feeds.

Super-sensitivity of the nipple to touch.

Constant loss of colour in the nipples or part or all of the areola .

Redness of the nipple.

Shooting pains radiating towards the chest wall, back, and shoulder.

Bilateral symptoms (except in the very early stages) because the infant transfers the infection.

A red flaky rash on the areola with itching or depigmentation.

Nipples that are slightly swollen with a shiny appearance, fissure of the nipple, or mild redness around the areola. The areola and nipple may also appear normal.

Blanching of the nipple — due to the pressure of suckling may cause pain and is related to poor breastfeeding technique.

Dermatitis of the nipple — presents as a red itchy rash with a well-demarcated edge.

Bacterial infection of the nipple. This may may present as a yellow discharge from the nipple or a sloughy appearance.

Herpes simplex viral infections of the breast.

Raynaud's disease of the nipple.

Blanching of the nipple is followed by cyanosis and/or erythema.

Pain is severe, debilitating, and throbbing.

Breastfeeding is very painful.

Symptoms are precipitated by cold and also occur during pregnancy and when not breastfeeding.

Conditions that cause pain and discomfort of the breast that are not related to lactation

Breast cancer, including inflammatory breast cancer.

Fibroadenosis.

Breast cyst — ruptured.

Sub-areolar abscess (duct ectasia).

Necrotizing fasciitis of the breasts.

Fat necrosis of the breast.

Paget's disease of the nipple.

Conditions of the chest wall

Costochondritis.

Mondor's disease (phlebitis of the chest wall).

Basis for recommendation

Basis for recommendation

This information is based on expert opinion from a review of the causes and management of mastitis and a review of infant and child feeding published by the World Health Organization [WHO, 2000; WHO, 2009], Guidelines on routine postnatal care for women and their babies published by the National Institute for Health and Care Excellence (NICE) [National Collaborating Centre for Primary Care, 2006], Guidelines on the treatment, management & prevention of mastitis for Northern Ireland published by the Guidelines and Audit Implementation Network [GAIN, 2009], Guidelines on thrush and breastfeeding published by the breastfeeding network[The Breastfeeding Network, 2009], review articles [Amir, 2003; Barbosa-Cesnik et al, 2003; Giordano and Hortobagyi, 2003; Mass, 2004; Fraser and Cullen, 2006; Betzold, 2007], a Cochrane systematic review protocol [Mangesi and Muzinzini, 2009], a textbook [Inch, 2000], case reports [Lawlor-Smith and Lawlor-Smith, 1997; Cyrlak and Carpenter, 1999; Anderson et al, 2004; Acarturk et al, 2005], and a pilot study [Graves et al, 2003].

Management

Management

Scenario: Management - breastfeeding women : covers the management of mastitis and conditions that predispose the woman to mastitis.

Scenario: Management - breast abscess : covers the management of breast abscess in primary care.

Scenario: Management - breastfeeding women

Scenario: Management of mastitis in breastfeeding women

120months3060monthsFemale

First-line management

What is the first-line management of mastitis?

Reassure the woman that although mastitis is a painful condition that may make her feel very ill, the breast will return to normal size, shape, and function.

Prescribe an antibiotic if:

Symptoms have not improved or are worsening after 12–24 hours despite effective milk removal.

The woman has a nipple fissure that is infected.

To relieve pain and discomfort:

Offer paracetamol as first choice.

Ibuprofen is an alternative. Use the lowest effective dose for the shortest possible time.

Advise the woman to:

Place a warm compress on the breast, or bathe or shower in warm water. This will relieve pain and help the milk to flow.

Rest, if this is possible.

Not wear a bra (especially at night).

Advise the woman to continue to breastfeed.

Involve a breastfeeding specialist to assist the woman in improving the infant's attachment to the breast. This will improve milk removal and prevent nipple damage.

If the affected breast is not completely empty after feeding, advise the woman to express the remaining milk by hand or by using a breast pump.

If breastfeeding is not possible, advise her to express breast milk by hand or pump until breastfeeding can be resumed.

Treat nipple damage — pain from nipple damage may inhibit effective milk removal. For more information, see Scenario: Nipple soreness - management in the CKS topic on Breastfeeding problems.

Advise the woman to contact a healthcare professional if:

Symptoms worsen.

Antibiotics have not been prescribed and symptoms have not settled within 12–24 hours.

Symptoms fail to settle after 48 hours of antibiotic treatment.

Basis for recommendation

Basis for recommendation

Reassurance of a positive outcome

Expert opinion in the guideline from the World Health Organization is that adequately treated, the outcome is a return to completely normal function and lactation. However, if mastitis is inadequately treated, there may be relapse — with more severe mastitis and permanent damage [WHO, 2000].

Relief of pain and discomfort

Analgesia

The National Institute for Health and Care Excellence (NICE) advises an analgesic compatible with breastfeeding, such as paracetamol [National Collaborating Centre for Primary Care, 2006].

For further information on the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in women who are breastfeeding, see the section on Breastfeeding in the CKS topic on NSAIDs - prescribing issues.

Warm compress, or bathe or shower with warm water

These recommendations are based on expert opinion in guidelines from the World Health Organization [WHO, 2000; WHO, 2009].

Rest

The recommendation to advise women with mastitis to rest is based on expert opinion in a guidelines from the World Health Organization (WHO) [WHO, 2000].

Information about not wearing a bra at night

This recommendation is based on expert opinion in a NICE guideline [National Collaborating Centre for Primary Care, 2006].

Continuing to breastfeed

The World Health Organization reviewed the available evidence and concluded that stopping breastfeeding does not help, and may make the woman worse [WHO, 2000].

Sudden cessation of breastfeeding is associated with a greater risk of abscess development compared with continuing to feed [Academy of Breastfeeding Medicine, 2008].

The only exception is women who are HIV positive, who have no alternative but to breastfeed, and who develop a fissure, mastitis, or an abscess. The infant may continue to feed from the unaffected side but milk from the affected breast should be expressed and discarded until the woman is fully recovered [WHO, 2000].

Mastitis increases the vertical transmission of HIV [WHO, 2000; Michie et al, 2003].

Involving a breastfeeding specialist

Good infant attachment is important to prevent further problems with milk stasis and infection, and to ensure successful feeding [National Collaborating Centre for Primary Care, 2006; GAIN, 2009].

Emptying the breast

This recommendation is based on expert opinion from NICE, which advises that 'the woman should continue breastfeeding and/or hand expression to ensure effective milk removal' [National Collaborating Centre for Primary Care, 2006]. Emptying of the breast after a feed is also advised by the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] and in a review article [Betzold, 2007]. The Breastfeeding Network also state that the woman may need to express milk after feeds [The Breastfeeding Network, 2006].

There is good evidence from a prospective study that regular emptying of the breast is important in the treatment of both infectious mastitis and non-infectious mastitis. There is also limited evidence from a small prospective study that emptying the breast and rest is curative in women with no pathogenic bacteria in their milk.

Expressing milk if breastfeeding is not possible

This recommendation is based on expert opinion from the World Health Organization [WHO, 2000].

Advice about when to contact a healthcare professional

These recommendations are based on advice from NICE [National Collaborating Centre for Primary Care, 2006].

Which antibiotic

Which antibiotic should I prescribe?

Antibiotic treatment is recommended for mastitis if the woman has a nipple fissure that is infected, symptoms do not improve or are worsening after 12–24 hours despite effective milk removal, or bacterial culture is positive.

If empirically treating infection:

Prescribe flucloxacillin 500 mg, four times a day, for 14 days.

An alternative is erythromycin 250 mg to 500 mg, four times a day, for 14 days.

Inform the woman that these antibiotics are only excreted in milk in very small amounts. Usually the infant is not affected, but occasionally stools may be looser or more frequent than usual or the infant may be more irritable.

If the results of breast milk culture are available, prescribe an antibiotic according to the sensitivities of the organism that has been identified.

It is unlikely that the infant will become unwell but, if staphylococcal or streptococcal infection is confirmed, observe the infant for signs of infection and seek the advice of a paediatrician if the child becomes unwell.

Basis for recommendation

Basis for recommendation

Choice of antibiotics

A Cochrane systematic review found insufficient evidence to evaluate the effectiveness of antibiotics in lactational mastitis.

Guidelines from the National Institute for Health and Care Excellence (NICE) [National Collaborating Centre for Primary Care, 2006] and the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] recommend a beta-lactamase resistant antibiotic for the treatment of infectious mastitis, based on expert opinion.

The Health Protection Agency recommends that broad spectrum antibiotics (such as co-amoxiclav) should be avoided when narrow spectrum antibiotics remain effective. Broad spectrum antibiotics increase the risk of Clostridium difficile and meticillin-resistant Staphylococcus aureus (MRSA) [HPA, 2009].

CKS therefore recommends flucloxacillin for first-line use, with erythromycin as an alternative (for women who cannot take penicillins). These antibiotics are usually effective against beta-lactamase producing organisms (such as Staphylococcus aureus), can be taken orally, and are considered to be suitable for use in women who are breastfeeding.

Penicillins (such as flucloxacillin) are the antibiotic of choice during breastfeeding, because only trace amounts are found in breast milk [Schaefer et al, 2007].

Erythromycin is excreted in breast milk in small amounts [Schaefer et al, 2007].

Length of antibiotic treatment course

Expert opinion in guidelines from the World Health Organization (WHO) [WHO, 2000] and the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] is that antibiotics should be prescribed for 10–14 days; however, the duration of antibiotic treatment has not been subject to controlled trials. Expert opinion is that relapse is more common with shorter courses of treatment [WHO, 2000]. CKS recommends a 14-day course of treatment, because this allows for original pack dispensing.

Risk of infection to the infant

Traditionally, healthcare workers were concerned about the risk of transmitting the infection to the infant if the woman continued to breastfeed (especially if the milk contained pus). A WHO review of the available evidence confirmed such fears are unfounded, with:

Six small studies (carried out between 1948 and 1988) reporting no harmful effects of continued breastfeeding.

Occasional case reports of staphylococcal scalded skin syndrome in infants of women with either mastitis or a breast abscess. However, it was not clear if transmission had been via close contact or through breast milk.

A few cases of transmission of Streptococcus group B infection from a woman with a breast abscess.

One case of transmission of salmonella infection to the infant (from salmonella mastitis).

The conclusion by WHO was that transmission of infection was rare and usually had a benign outcome.

The recommendation that if mastitis is known to be due to staphylococcal or streptococcal infection, the infant should be observed for signs of infection and simultaneous treatment considered is based on expert opinion in guidelines from WHO [WHO, 2000]. CKS advises seeking specialist advice if the infant becomes unwell to determine whether admission or antibiotic treatment is appropriate.

Information about breastfeeding

What information about breastfeeding should I offer a woman with mastitis?

Advise the woman to continue breastfeeding.

Explain that breastfeeding is extremely beneficial and continuing to breastfeed with mastitis will not harm the infant.

Inform the woman:

To breastfeed on demand with no restrictions on frequency and length of feeds.

To minimize nipple discomfort, start feeding on the unaffected breast and once let-down occurs switch to the affected breast.

If necessary, gently massage the breast to overcome blockage and help milk flow. Massage should be directed from the blocked area moving towards the nipple.

To drink sufficient fluids.

Advise the woman to express milk by hand or with a pump if the:

Affected breast is not completely empty after feeding.

Infant appears to dislike the taste of the milk from the affected breast (which is more salty and less sweet). Milk from this breast can be discarded.

Breast becomes full between feeds. Alternatively allow the milk to flow freely in a hot bath or shower.

Basis for recommendation

Basis for recommendation

Continuing to breastfeed

The World Health Organization reviewed the available evidence and concluded that stopping breastfeeding does not help, and may make the woman worse [WHO, 2000].

Sudden cessation of breastfeeding is associated with a greater risk of abscess development compared with continuing to feed [Academy of Breastfeeding Medicine, 2008].

Advice about how to breastfeed

These recommendations are based on expert opinion from the World Health Organization [WHO, 2000], Guidelines on the treatment, management & prevention of mastitis for Northern Ireland published by the Guidelines and Audit Implementation Network [GAIN, 2009], the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008], the National Institute for Health and Care Excellence (NICE) [National Collaborating Centre for Primary Care, 2006], and review articles [Mass, 2004; Betzold, 2007; Spencer, 2008].

Encourage fluids

This recommendation is based on expert advice from the the National Institute for Health and Care Excellence (NICE) [National Collaborating Centre for Primary Care, 2006].

Emptying the breast

This recommendation is based on expert opinion from NICE, which advises that 'the woman should continue breastfeeding and/or hand expression to ensure effective milk removal' [National Collaborating Centre for Primary Care, 2006]. Emptying of the breast after a feed is also advised by the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] and in a review article [Betzold, 2007]. The Breastfeeding Network also state that the woman may need to express milk after feeds [The Breastfeeding Network, 2006].

There is good evidence from a prospective study that regular emptying of the breast is important in the treatment of both infectious mastitis and non-infectious mastitis. There is also limited evidence from a small prospective study that emptying the breast and rest is curative in women with no pathogenic bacteria in their milk.

Change in taste of the milk

Inflammation of the breast causes the tight junctions between the milk secreting cells of the alveoli to open up and substances from plasma to pass into the milk. The increased pressure causes substances from the milk to pass into the tissues. Therefore, there is an increase of sodium chloride and a decrease of potassium and lactose in the milk, leading to a change in its taste [WHO, 2000; The Breastfeeding Network, 2006 Betzold, 2007; Spencer, 2008].

Expressing milk between feeds

The Breastfeeding Network advise that milk needs to be flowing freely to relieve symptoms [The Breastfeeding Network, 2006].

Expressing breast milk

How do I support a woman to express breast milk?

Expressing breast milk should not be rushed. Explain that to express an adequate amount of breast milk may take up to 30 minutes.

Teach the woman to express breast milk herself. Recommend the following:

Have a clean, sterilized, wide-necked container available.

Wash her hands thoroughly.

Sit or stand comfortably, and hold the container under her nipple and areola.

Gently massage the breast and nipple before expressing.

Cup her breast in her hands and feel back from the end of the nipple to the area where the breast feels different.

Put her thumb on her breast ABOVE the nipple and areola, and her first finger on the breast BELOW the nipple and areola, opposite the thumb. Support the breast with her other fingers.

Gently squeeze, this should not hurt. if it hurts, the technique is wrong.

Release the pressure and repeat building up a rhythm.

At first no milk or only drops may come but after squeezing gently a few times, milk should start to drip out. It may flow in streams.

If the milk does not flow at all, try moving the fingers either a little way towards the nipple or a little further away.

When the flow slows move to the other breast.

Keep changing breasts until the milk stops or drips very slowly.

Avoid:

Rubbing or sliding the fingers along the skin.

Squeezing or pinching the nipple.

Basis for recommendation

Basis for recommendation

This information is based on advice from the Department of Health [DH, 2007], advice from the World Health Organization guidelines on mastitis [WHO, 2000], and guidelines on infant and young child feeding [WHO, 2009].

Treatment failure

How should I treat a woman who has not responded to first-line treatment for mastitis?

If the woman's symptoms do not improve after 12–24 hours despite effective milk removal, prescribe an antibiotic (if this has not already been done).

If symptoms fail to settle after 48 hours of antibiotic treatment:

Check that the woman has taken the antibiotic correctly.

Send a sample of the milk for culture.

Prescribe a different antibiotic for 14 days.

If culture results are available, treat with an antibiotic the organism is sensitive to.

If culture results are not available, treat empirically with co-amoxiclav 500/125 mg, three times a day. Seek specialist advice if the woman is unable to take penicillin. Review when culture results are available.

Consider an alternative diagnosis.

If there is an underlying mass, or ductal cancer or inflammatory breast cancer (a rapid onset of warmth of the breast, diffuse redness (varies from a faint blush to bright red) and oedema causing an orange skin [peau d'orange] appearance) is suspected, arrange urgent investigation or referral.

If a localized area of the breast remains hard, red, and tender — suspect an abscess. Malaise and fever may have subsided if antibiotics have been taken. Refer the woman to a general surgeon for confirmation of the diagnosis (by ultrasound), and for drainage of the abscess (by ultrasound-guided needle aspiration [this often needs to be repeated] or surgical drainage). Culture of fluid from the abscess is used to guide the choice of antibiotic.

If the infant has tongue-tie (ankyloglossia) and concerns about breastfeeding persist after a review of attachment and positioning, refer the infant (non-urgently) for consideration of frenulotomy.

Basis for recommendation

Basis for recommendation

Checking that the woman has taken the antibiotic correctly

An inadequately short course of antibiotic, and failure to complete an antibiotic course, have been associated with a higher incidence of relapse [WHO, 2000; Deshpande, 2007].

Culture of milk

The recommendation to send the woman's milk for culture if symptoms fail to settle within 12–24 hours is based on expert opinion in guidelines from the World Health Organization (WHO) [WHO, 2000].

Choice of second-line antibiotic

A Cochrane systematic review found insufficient evidence to evaluate the effectiveness of antibiotics in lactational mastitis.

Guidelines from the National Institute for Health and Care Excellence (NICE) [National Collaborating Centre for Primary Care, 2006] and the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] recommend a beta-lactamase resistant antibiotic for the treatment of infectious mastitis, based on expert opinion.

If the infection has not responded adequately to flucloxacillin and empirical treatment is required, CKS recommends prescribing co-amoxiclav (because it is a beta-lactamase resistant antibiotic that has a broader spectrum of activity than flucloxacillin). It can be taken orally, and is suitable for use in primary care.

Penicillins (such as co-amoxiclav) are the antibiotic of choice during breastfeeding, because only trace amounts are found in breast milk [Schaefer et al, 2007].

Length of antibiotic course

The recommendation to prescribe antibiotic treatment for 10–14 days is based on expert opinion in WHO guidelines [WHO, 2000] and guidelines from the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008]. Expert opinion is that relapse is more common with shorter courses of treatment.

Urgent investigation/referral if an underlying mass is found or inflammatory breast cancer or ductal cancer is suspected

These recommendations are based on accepted good clinical practice.

Inflammatory breast cancer may present with a rapid onset of warmth of the breast, diffuse redness (varies from a faint blush to bright red) and oedema causing an orange skin (peau d'orange) appearance [Giordano and Hortobagyi, 2003].

Suspicion of an abscess

These recommendations are based on expert opinion in narrative reviews [Mass, 2004; Betzold, 2007; Spencer, 2008].

Referral for frenulotomy

This recommendation is based on expert opinion in NICE guidelines [National Collaborating Centre for Primary Care, 2006].

Recurrent mastitis

How should I treat a woman with recurrent mastitis?

If the woman has recurrent mastitis, look for an underlying cause.

Check that all the predisposing factors for milk stasis and infection have been addressed, particularly uncorrected breastfeeding technique.

Treat nipple damage. Consider the possibility of candidal infection of the nipple; if this is present, treat both the woman and the infant. For more information, see Scenario: Nipple soreness - management in the CKS topic on Breastfeeding problems.

Check that previous episodes of mastitis have been treated with an appropriate antibiotic for 10–14 days.

Ask if the woman has been using potentially-contaminated nipple ointments or breast pumps.

Send nasal swabs from both woman and infant to identify nasal carriage of Staphylococcus aureus. If this is present, treat it with mupirocin cream. For further information, see the section on Decolonization in the CKS topic on Boils, carbuncles, and staphylococcal carriage.

Consider the possibility of an underlying inflammatory cancer that may mimic mastitis.

Consider trauma (including from domestic violence).

If there are more that two recurrences in the same location, consider the possibility of an underlying lesion that is leading to persistently poor drainage:

Abnormal ducts.

Cyst.

Tumour.

Send breast milk for microscopy, culture, and antibiotic sensitivity. See Investigations.

If there is an underlying mass, or ductal cancer or inflammatory breast cancer (a rapid onset of warmth of the breast, diffuse redness (varies from a faint blush to bright red) and oedema causing an orange skin [peau d'orange] appearance) is suspected, arrange urgent investigation or referral.

Treat each episode of mastitis promptly with an antibiotic for 14 days.

Choice of antibiotic should be guided by culture and sensitivity results, where available.

For empirical treatment, prescribe co-amoxiclav 500/125 mg, three times a day, for 14 days. Review when results of culture are available.

Seek specialist advice if the woman is unable to take penicillin.

Basis for recommendation

Basis for recommendation

Consider a possible underlying cause

These recommendations are based on expert opinion in guidelines from the World Health Organization (WHO) [WHO, 2000], the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008], and narrative reviews [Betzold, 2007; Deshpande, 2007].

Candidal infection of the nipple is associated with recurrent mastitis. This is probably because [WHO, 2000]:

Candidal infection predisposes to nipple fissure, which is an entry point for bacterial infection.

The nipples are damaged and painful, so the breast is used less — causing milk stasis.

The recommendation to look for nasal carriage of Staphylococcus aureus is based on expert opinion from a narrative review [Betzold, 2007].

Sending breast milk for culture

These recommendations are based on expert opinion in WHO guidelines [WHO, 2000] and a narrative review [Betzold, 2007].

Urgent investigation/referral if an underlying mass is found or inflammatory breast cancer or ductal cancer is suspected

These recommendations are based on accepted good clinical practice.

Inflammatory breast cancer may present with a rapid onset of warmth of the breast, diffuse redness (varies from a faint blush to bright red) and oedema causing an orange skin (peau d'orange) appearance [Giordano and Hortobagyi, 2003].

The importance of investigation and prompt treatment of recurrent mastitis

Prompt investigation and treatment of recurrent mastitis is important to prevent widespread lesions, irreversible tissue damage, breast disfigurement, and chronic inflammation [WHO, 2000; Betzold, 2007].

Antibiotic choice

A Cochrane systematic review found insufficient evidence to evaluate the effectiveness of antibiotics in lactational mastitis.

Guidelines from the National Institute for Health and Care Excellence (NICE) [National Collaborating Centre for Primary Care, 2006] and the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008] recommend a beta-lactamase resistant antibiotic for the treatment of infectious mastitis, based on expert opinion.

If the infection recurs after appropriate treatment with flucloxacillin and empirical treatment is required, CKS recommends prescribing co-amoxiclav (as it is a beta-lactamase resistant antibiotic that has a broader spectrum of activity than flucloxacillin). It can be taken orally and is suitable for use in primary care.

Penicillins (such as co-amoxiclav) are the antibiotic of choice during breastfeeding, because only trace amounts are found in breast milk [Schaefer et al, 2007].

Refer or admit

When should I refer or admit a woman with mastitis?

Admit the woman if she is extremely unwell. The infant should be admitted with her, to allow continuation of breastfeeding.

Most women with mastitis do not need admitting to hospital.

If there is an underlying mass, or ductal cancer or inflammatory breast cancer (a rapid onset of warmth of the breast, diffuse redness [varies from a faint blush to bright red] and oedema causing an orange skin [peau d'orange] appearance) is suspected, arrange urgent investigation or referral.

If a localized area of the breast remains hard, red, and tender, suspect an abscess and refer the woman to a general surgeon for confirmation of the diagnosis (by ultrasound), and for drainage of the abscess (by ultrasound-guided needle aspiration or surgical drainage).

Basis for recommendation

Basis for recommendation

Admittance to hospital

This recommendation is based on expert advice from the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008].

Urgent investigation/referral if an underlying mass is found or inflammatory breast cancer or ductal cancer is suspected

These recommendations are based on accepted good clinical practice.

Inflammatory breast cancer may present with a rapid onset of warmth of the breast, diffuse redness (varies from a faint blush to bright red) and oedema causing an orange skin (peau d'orange) appearance [Giordano and Hortobagyi, 2003].

Referral for suspected abscess

This recommendations is based on expert opinion in narrative reviews [Mass, 2004; Betzold, 2007; Spencer, 2008].

Preventing future problems

What advice should I give to prevent future problems?

Explain that good breastfeeding technique (good attachment and effective milk removal) is necessary to prevent mastitis.

To prevent future problems, advise the woman to:

Make sure the infant is attached correctly.

Feed on demand, both for the frequency and duration of feeds.

Avoid missed feeds, especially when the infant starts to sleep through the night.

Finish the first breast before offering the other.

Breastfeed exclusively for 4–6 months, if possible. Avoid other foods and drinks, especially from a feeding bottle.

Avoid the use of a dummy (pacifier).

For future pregnancies, start to breastfeed within an hour of delivery, if possible.

Ensure that the woman knows:

How to express milk manually (for if the infant is not able to attach because the breast is too full, or if the infant is not able to empty the breast).

How to check breasts for lumps, redness, and tenderness.

How to recognize milk stasis, and that if this develops she needs to rest, breastfeed frequently, massage any lumpy area, and seek help if problems do not resolve within 24 hours.

That damaged or painful nipples or an inadequate milk supply are not urgent concerns (and do not require same-day help).

To seek help if any other concerns do not resolve within 24 hours.

Weaning

If the woman does not wish to continue breastfeeding, give advice about suppression of lactation:

Avoid abrupt weaning.

Support the breasts with a comfortable bra or binding.

Express enough milk to keep the breasts comfortable.

Prescribe ibuprofen or paracetamol if pain occurs.

Do not prescribe stilboestrol, oestrogen (either alone or with testosterone), bromocriptine, or cabergoline to stop lactation.

Basis for recommendation

Basis for recommendation

Recommendations on good breastfeeding technique

These recommendations are based on expert opinion in guidelines from the World Health Organization (WHO) [WHO, 2000], the Academy of Breastfeeding Medicine [Academy of Breastfeeding Medicine, 2008], and the National Institute for Health and Care Excellence [National Collaborating Centre for Primary Care, 2006].

Advice on weaning

These recommendations are based on expert opinion in WHO guidelines [WHO, 2000].

Drugs to stop lactation

Expert opinion in WHO guidelines is that the following drugs should not be used [WHO, 2000]:

Stilboestrol — there is a risk of thromboembolism, withdrawal bleeding, and recurrence of engorgement when it is discontinued.

Oestrogen, alone or in combination with testosterone — there is a risk of thromboembolism, it is not very effective, and engorgement may occur when it is discontinued.

Bromocriptine — there is a risk of myocardial infarction, hypertension, seizures and strokes. Also dizziness, hypotension, nausea, and severe headache can occur.

Cabergoline — headache, dizziness, hypotension, and epistaxis can occur.

Scenario: Management - breast abscess

Scenario: Management of breast abscess

120months3060monthsFemale

Management

How should I manage a woman with a breast abscess

Refer the woman urgently to a general surgeon for:

Confirmation of the diagnosis (by ultrasonography).

Drainage of the abscess by ultrasonography-guided needle aspiration (this often needs to be repeated) or surgical drainage.

Culture of fluid from the abscess which will be used to guide the choice of antibiotic.

Basis for recommendation

Basis for recommendation

This recommendation is based on expert opinion from a review of the causes and management of mastitis published by the World Health Organization [WHO, 2000].

A thoroughly performed, ultrasonography-guided aspiration may be curative and can be done under local anaesthetic as an outpatient.

Antibiotics alone without removal of pus are unlikely to be curative.

Information about breastfeeding

What information about breastfeeding should I offer a women with a breast abscess?

Inform the woman:

That continued breastfeeding is safe for the infant.

To continue breastfeeding from the unaffected breast.

If breastfeeding is too painful from the affected breast then breast milk should be expressed until she is able to resume breastfeeding from that breast.

To resume breastfeeding from the affected breast as soon as the pain is less.

Basis for recommendation

Basis for recommendation

These recommendations are based on expert advice in Guidelines on the treatment, management & prevention of mastitis for Northern Ireland published by the Guidelines and Audit Implementation Network [GAIN, 2009] and in guidelines on infant and young child feeding from the World Health Organization [WHO, 2009].

Important aspects of prescribing information relevant to primary healthcare are covered in this section specifically for the drugs recommended in this CKS topic. For further information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://medicines.org.uk/emc), or the British National Formulary (BNF) (www.bnf.org).

Oral antibiotics

Oral antibiotics

Penicillins (such as flucloxacillin and co-amoxiclav) are the antibiotic of choice during breastfeeding because they are effective against beta-lactamase producing organisms (such as Staphylococcus aureus) and only trace amounts are found in breast milk [Schaefer et al, 2007].

Erythromycin is an alternative where a beta-lactamase producing organism is the likely cause of infection. It is excreted in breast milk in small amounts, so erythromycin is reserved for women with penicillin allergy. Erythromycin should be avoided if the neonate has jaundice. There are case reports of pyloric stenosis in neonates being breastfed by mothers taking erythromycin, but causality has not been established [Schaefer et al, 2007].

Avoid flucloxacillin and co-amoxiclav in women with hepatic impairment, or a history of hepatic dysfunction associated with their use.

The Commission on Human Medicines (formerly the CSM) advises that flucloxacillin has been associated with a very small increased risk of hepatic disorders, namely hepatitis and cholestatic jaundice. Hepatic reactions may occur up to 2 months after treatment with flucloxacillin has stopped. Risk factors include treatment for more than 14 days and increasing age. The dose and route of administration do not appear to affect this risk [CSM, 2004].

The Commission on Human Medicines advises that cholestatic jaundice may rarely occur during or shortly after the use of co-amoxiclav [CSM, 1997]. This is more common in men, in people older than 65 years of age, and with longer courses of treatment (more than 14 days).

Consider the possibility of drug interactions before prescribing erythromycin.

Evidence

Evidence

Supporting evidence

CKS identified no studies on the diagnosis of mastitis, and therefore recommendations about diagnosis (including investigations) are based on expert opinion in guidelines.

CKS reviewed the evidence on the usefulness of milk culture, on emptying the breasts regularly, on the use of antibiotics for treating mastitis, and on treating a nipple fissure.

Usefulness of milk culture

Evidence for the usefulness of milk culture in mastitis

Limited evidence from a small prospective study suggests that milk culture is useful for identifying potentially pathogenic bacteria, informing the decision on whether to treat with antibiotics. Emptying the breast and rest is curative in women with no pathogenic bacteria in their milk.

A prospective study compared laboratory findings, clinical signs, treatment, and outcomes in 41 women with lactation mastitis [Osterman and Rahm, 2000]. The women were grouped according to the bacteria cultured from their breast milk. Both groups of women had high temperatures (mean 39.3°C). All the women were encouraged to empty their breast frequently (by breastfeeding and hand expression, or mechanical expression of milk).

One group of 25 women had bacteria in their milk that are normally present on skin. All continued to breastfeed, none had symptoms for more than a week, and no severe complications were observed.

The other group of 16 women had potentially pathogenic bacteria in their milk (primarily Staphylococcus aureus) but a few were infected with beta-haemolytic streptococci. Nine women received antibiotics. This group generally had poorer outcomes, with five choosing to wean their infant, one who had a breast abscess, and one who experienced septic fever. Symptoms resolved within a week in only three women.

Sore nipples were strongly associated with the presence of pathogenic bacteria (p < 0.0001) and the authors recommended antibiotics for these women.

The authors concluded that:

Rest and thorough emptying of the breast was curative in women who had only bacteria normally present on the skin in their milk.

Women with potentially pathogenic bacteria are at risk of complications and should receive treatment with antibiotics.

Emptying the breast regularly

Evidence for emptying the breast regularly in mastitis

Good evidence from a prospective study shows that regular emptying of the breast is important in the treatment of both infectious mastitis and non-infectious mastitis.

A randomized study investigated the duration and outcome of milk stasis, non-infectious mastitis, and infectious mastitis. The study included 213 breastfeeding women with 339 breasts with inflammatory symptoms [Thomsen et al, 1984]. Outcomes were expressed in terms of the number of breasts and not the number of women.

Women were classified according to bacterial and leucocyte counts in their milk:

Milk stasis: low bacterial counts and low leucocyte counts.

Non-infectious mastitis: low bacterial counts and high leucocyte counts.

Infectious mastitis: high bacterial counts and high leucocyte counts.

Within each group, the women were randomized to receive treatment or no treatment. Treatment consisted of emptying the breast every 6 hours; some women in this group also received antibiotics.

A good outcome was defined as resolution of symptoms and continuation of breastfeeding within 2 weeks.

A bad outcome was defined as persistence of symptoms for more than 14 days, impaired milk secretion, recurrence of infection, or progression to sepsis or a breast abscess.

The results showed that:

Most women with milk stasis had a good outcome and emptying the breast regularly had only a symptomatic effect at best.

Regular emptying of the breast significantly shortened the duration of symptoms in women with non-infectious mastitis: 96% of breasts in women who regularly emptied their breasts had a good outcome compared with 21% of breasts in women who received no treatment (p < 0.001). Without effective removal of milk, non-infectious mastitis was likely to progress to infectious mastitis.

In women with infectious mastitis, regular emptying of the breast significantly shortened the duration of symptoms (p < 0.001) and there was a good outcome in 51% of breasts compared with 15% of breasts in the group who received no treatment. Antibiotics further improved the situation, producing a good outcome in 96% of breasts (p < 0.001). Without effective removal of milk, infectious mastitis was likely to progress to abscess formation.

Antibiotics - lactational mastitis

Evidence for the use of antibiotics in women with lactational mastitis

There is insufficient evidence to evaluate the effectiveness of antibiotics in lactational mastitis.

A Cochrane systematic review examined the effectiveness of antibiotics in relieving the symptoms of mastitis in breastfeeding women [Jahanfar et al, 2009].

Two trials met the inclusion criteria.

A small, prospective, randomized, single-blinded trial of 25 women with acute puerperal mastitis found no difference in outcomes (cure rate, recurrence within 30 days, and time to resolution of symptoms) between the 13 women who received amoxicillin (500 mg three times day for 7 days) and the 12 women who received cephradine (500 mg four times a day for 7 days) [Hager and Barton, 1996].

The other study compared treatment versus no treatment. Treatment consisted of emptying the breast every 6 hours; some women in this group also received antibiotics [Thomsen et al, 1984]. The results suggested that antibiotic treatment was associated with faster resolution of symptoms.

The authors concluded that there was insufficient evidence to be able to evaluate the effectiveness of antibiotic treatment in women with lactational mastitis.

Antibiotics - staphylococcal aureus

Evidence for the use of antibiotics in women with a nipple fissure infected with staphylococcal aureus

Limited evidence from a small, randomized, prospective study suggests that breastfeeding women with sore nipples with a break in the skin from which Staphylococcus aureus had been cultured were more likely to improve and less likely to develop mastitis if treated with oral antibiotics rather than a topical antibiotic (fusidic acid or mupirocin).

A prospective, randomized trial compared four treatments in 84 women who had sore nipples with a break in the skin from which S. aureus had been cultured [Livingstone and Stringer, 1999]. The women received one-to-one instruction on breastfeeding technique plus a video, and one of four treatments: no antibiotics; topical mupirocin; topical fusidic acid; and oral cloxacillin or erythromycin.

The women were randomly allocated to four groups and assessed after 5–7 days.

No antibiotic treatment — only 9% of women improved and 30% developed mastitis.

Topical 2% mupirocin (ointment applied to the nipples after each feed) — 16% of women improved and 12% developed mastitis.

Topical fusidic (ointment applied to the nipples after each feed) — 36% of women improved and 21% developed mastitis.

Oral cloxacillin or erythromycin (500 mg every 6 hours for 10 days) — 79% of women improved and 5% developed mastitis.

Women treated with oral antibiotics were more likely to improve (p < 0.0001) and were less likely to develop mastitis (p < 0.005) compared with women treated with topical antibiotics, or those receiving no treatment (except for optimal breastfeeding technique).

Search strategy

Scope of search

A literature search was conducted for guidelines, systematic reviews and randomized controlled trials on primary care management of mastitis.

Search dates

Dates not restricted – December 2009

Key search terms

Various combinations of searches were carried out. The terms listed below are the core search terms that were used for Medline and these were adapted for other databases. Further details are available on request.

mastitis/, mastitis.tw, breast feeding/ exp lactation/

Table 1 . Key to search terms.
Search commands Explanation
/ indicates a MeSh subject heading with all subheadings selected
.tw indicates a search for a term in the title or abstract
exp indicates that the MeSH subject heading was exploded to include the narrower, more specific terms beneath it in the MeSH tree
$ indicates that the search term was truncated (e.g. wart$ searches for wart and warts)
Topic specific literature search sources

The Breastfeeding Network

Sources of guidelines

National Institute for Health and Care Excellence (NICE)

Scottish Intercollegiate Guidelines Network (SIGN)

National Guidelines Clearinghouse

New Zealand Guidelines Group

British Columbia Medical Association

Canadian Medical Association

Institute for Clinical Systems Improvement

Guidelines International Network

National Library of Guidelines

National Health and Medical Research Council (Australia)

Alberta Medical Association

University of Michigan Medical School

Michigan Quality Improvement Consortium

Royal College of Nursing

Singapore Ministry of Health

Health Protection Agency

National Resource for Infection Control

CREST

World Health Organization

NHS Scotland National Patient Pathways

Agency for Healthcare Research and Quality

TRIP database

Patient UK Guideline links

UK Ambulance Service Clinical Practice Guidelines

RefHELP NHS Lothian Referral Guidelines

Medline (with guideline filter)

Sources of systematic reviews and meta-analyses

The Cochrane Library :

Systematic reviews

Protocols

Database of Abstracts of Reviews of Effects

Medline (with systematic review filter)

EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

NIHR Health Technology Assessment programme

The Cochrane Library :

NHS Economic Evaluations

Health Technology Assessments

Canadian Agency for Drugs and Technologies in Health

International Network of Agencies for Health Technology Assessment

Sources of randomized controlled trials

The Cochrane Library :

Central Register of Controlled Trials

Medline (with randomized controlled trial filter)

EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

Bandolier

Drug & Therapeutics Bulletin

MeReC

NPCi

BMJ Clinical Evidence

DynaMed

TRIP database

Central Services Agency COMPASS Therapeutic Notes

Sources of national policy

Department of Health

Health Management Information Consortium (HMIC)

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