Clinical Topic A-Z Clinical Speciality

Insect bites and stings

Insect bites and stings
D007299Insect Bites and Stings
AllergiesInjuries
2011-11-01Last revised in November 2011

Insect bites and stings - Summary

An insect bite is a puncture wound or laceration inflicted by an insect. Biting insects commonly encountered in the UK include: midges, gnats, mosquitoes, flies, fleas, and bedbugs. Bites from ticks and mites are also common in the UK.

Some insects have a stinging apparatus, which consists of a sac of venom attached to a barbed or non-barbed stinger. The sting occurs when the sac contracts and venom is deposited into the tissue. Stinging insects commonly encountered in the UK include honeybees, bumblebees, wasps, and hornets.

Most insect bite reactions resolve quickly, although more persistent reactions are likely with tick bites. Complications of insect bites include secondary bacterial infection from scratching, and diseases that may be transmitted following a bite, such as Lyme disease and malaria.

Most insect stings produce a transient local reaction that lasts for several days and generally resolves without treatment. Complications of insect stings include fever and malaise, systemic toxic effects (from multiple stings), serum sickness-like reaction (rare), and anaphylaxis.

Small local reactions to insect bites or stings present with localized pain, swelling, and erythema at the site of the bite or sting. Most can be managed symptomatically:

The stinger should be removed as soon as possible by flicking or scraping it with a fingernail, piece of card, or knife blade. Ticks should also be removed as soon as possible.

The area of the bite or sting should be washed with soap and water.

Scratching should be avoided, as this will cause the site to swell and itch more, and increase the chance of infection.

Local pain and oedema can be managed with cold compresses and oral analgesics (paracetamol or ibuprofen).

Local itching can be treated with topical crotamiton or a mild potency topical corticosteroid (e.g. hydrocortisone 1%). If the itch is affecting sleep, an oral sedating antihistamine at night may help.

Large local reactions present with severe pain, and oedema that extends beyond the site of the sting or bite. Most can be managed symptomatically:

Pain can be managed with an oral analgesic (paracetamol or ibuprofen).

Itching can be treated with an oral antihistamine; if local swelling is severe, a short course of an oral corticosteroid may be used.

If a severe systemic reaction occurs, such as wheezing or other signs of respiratory distress, or hypotension, or there are symptoms of systemic toxicity that suggest impending anaphylaxis (e.g. abdominal pain, vomiting, rhinitis and conjunctivitis, or a sense of impending doom), treat as for anaphylaxis and admit to hospital.

If the bite or sting appears infected, empirical antibiotic treatment should be started (flucloxacillin is recommended, or a macrolide for people with penicillin allergy).

Have I got the right topic?

1months3060monthsBoth

This CKS topic covers insect bites and stings, including bites from ticks and mites.

This CKS topic does not cover spider bites or bites from insects that are not indigenous to the UK. This CKS topic does not discuss the management of anaphylaxis, as there is a separate CKS topic on Angio-oedema and anaphylaxis.

There are separate CKS topics on Bites - human and animal, Head lice, Malaria prophylaxis, and Scabies.

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 November 2011

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].

June 2012 - minor update. Minor typographical error corrected.

October 2011 — reviewed. A literature search was conducted in October 2011 to identify evidence-based guidelines, UK policy, systematic reviews, and key RCTs published since the last revision of the topic. No changes to clinical recommendations have been made. Issued in November 2011.

Previous changes

July 2011 — minor update. More exact paracetamol dosing for children has been introduced by the Medicines and Healthcare products Regulatory Agency [MHRA, 2011]. Prescriptions have been updated to reflect the revised dosing. Issued in July 2011.

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

March 2011 — topic structure revised to ensure consistency across CKS topics — no changes to clinical recommendations have been made.

May 2008 — minor text update. Issued in June 2008.

January 2008 — minor text update to the choice of antihistamines to treat urticaria. Issued in February 2008.

July 2007 — minor text update to Risk factors for being stung or bitten. Issued in August 2007.

January to April 2007 — converted from CKS guidance to CKS topic structure. The evidence-base has been reviewed in detail, and recommendations are more clearly justified and transparently linked to the supporting evidence.

There are no major changes to the recommendations.

October 2003 — written. Validated in December 2003 year and issued in February 2004.

Update

New evidence

Evidence-based guidelines

No new evidence-based guidelines published since 1 October 2011.

HTAs (Health Technology Assessments)

Technology appraisals published since the last revision of the topic:

NICE (2012) Pharmalgen for the treatment of systematic reactions to bee and wasp venom allergy. NICE technology appraisal guidance 246. National Institute for Health and Clinical Excellence. www.nice.org.uk [Free Full-text]

Health technology assessments published since the last revision of this topic:

Hockenhull, J., Elremeli, M., Cherry, M., et al. (2012) A systematic review of the clinical effectiveness and cost-effectiveness of Pharmalgen® for the treatment of bee and wasp venom allergy. Health Technology Assessment 16(12), 1-110. [Abstract] [Free Full-text]

Economic appraisals

No new economic appraisals relevant to England since 1 October 2011.

Systematic reviews and meta-analyses

Systematic reviews published since the last revision of this topic:

Boyle, R.J., Elremeli, M., Hockenhull, J. Et al. (2012) Venom immunotherapy for preventing allergic reactions to insect stings (Cochrane Review). The Cochrane Library. Issue 10. John Wiley & Sons, Ltd. www.thecochranelibrary.com [Free Full-text]

Primary evidence

No new randomized controlled trials published in the major journals since 1 October 2011.

New policies

No new national policies or guidelines since 1 October 2011.

New safety alerts

No new safety alerts since 1 October 2011.

Changes in product availability

No changes in product availability since 1 October 2011.

Goals and outcome measures

Goals

To relieve symptoms

To treat anaphylaxis promptly

To prevent reinfestation (e.g. by fleas and bedbugs)

To minimize the risk of future anaphylactic reactions

QIPP - options for local implementation

QIPP - options for local implementation

Non-steroidal anti-inflammatory drugs (NSAIDs)

Review the appropriateness of NSAID prescribing widely and on a routine basis, especially in people who are at higher risk of both gastrointestinal (GI) and cardiovascular (CV) morbidity and mortality (e.g. older patients).

If initiating an NSAID is obligatory, use ibuprofen (1200 mg per day or less) or naproxen (1000 mg per day or less).

Review patients currently prescribed NSAIDs. If continued use is necessary, consider changing to ibuprofen (1200 mg per day or less) or naproxen (1000 mg per day or less).

Review and, where appropriate, revise prescribing of etoricoxib to ensure it is in line with MHRA advice and the NICE clinical guideline on osteoarthritis [CSM, 2005; NICE, 2008].

Co-prescribe a proton pump inhibitor (PPI) with NSAIDs for people with osteoarthritis, rheumatoid arthritis, or low back pain (for people over 45 years) in accordance with NICE guidance [NICE, 2008; NICE, 2009a; NICE, 2009b].

Take account of drug interactions when co-prescribing NSAIDs with other medicines (see Summaries of Product Characteristics). For example, co-prescribing NSAIDs with ACE inhibitors or angiotensin receptor blockers (ARBs) may pose particular risks to renal function; this combination should be especially carefully considered and regularly monitored if continued.

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?

Definition of insect bite

What is an insect bite?

An insect bite is a puncture wound or laceration inflicted by an insect.

The presence of antigenic salivary gland secretions in the insect bite produces local inflammation, and can result in systemic effects.

The type of local reaction provoked mainly depends on previous exposure to the same or related species, typically:

The first time a person is bitten there is often no reaction unless the salivary secretions of the insect contain a directly injurious substance.

After repeated bites, as sensitivity occurs, an itchy papule develops about 24 hours after each bite, and persists for several days.

After further bites, an extremely itchy weal develops immediately. This lasts about 2 hours, and is followed by a firm pruritic papule about 24 hours later, which usually persists for several days.

With continued and repeated exposure, the delayed papule reaction no longer occurs and eventually there is no reaction at all.

Biting insects commonly encountered in the UK include: midges, gnats, mosquitoes, flies, fleas, and bedbugs. Bites from ticks and mites are also common in the UK.

[Millikan, 1993; Burns, 2004]

Definition of insect sting

What is an insect sting?

Stinging insects commonly encountered in the UK include honeybees, bumblebees, wasps, and hornets.

The stinging apparatus consists of a sac of venom attached to a barbed or non-barbed stinger. The sting occurs when the sac contracts and venom is deposited into the tissue.

Honey bee stingers are barbed, which causes the stinging apparatus to detach from the insect, resulting in its death. The injection mechanism continues to operate even after separation from the insect.

Venom contains allergens (e.g. phospholipases, hyaluronidase) and pharmacologically active substances (e.g. histamine, serotonin) which cause a reaction in the person who has been stung. This reaction ranges from localized pain, erythema, and swelling at the site of the sting, to a severe systemic reaction (anaphylaxis).

The severity of a reaction to a sting is determined by the quantity of pharmacologically active substance deposited, and the degree of hypersensitivity to the antigenic substance.

The antigenic substances in the venom of bees, wasps, and hornets are more likely to induce severe systemic hypersensitivity reactions than the antigens of most other insects.

[Reisman, 1994; Ewan, 1998; Burns, 2004]

Prevalence of insect bites and stings

How common are insect bites and stings?

The incidence and prevalence of insect bites and stings are unknown.

Risk factors for being stung or bitten

What are the risk factors for being stung or bitten?

Occupation: bee keepers are at risk of bee stings; dock workers handling food stuff may be attacked by mites; forestry workers are at higher risk of bites from ticks or midges.

Outdoor activities and travel: backpacking, walking in tick-infested areas (picnickers are at risk where there is food around, particularly from wasps).

Clothing: exposed skin areas increase the risk of insect bites.

Possession of a domestic animal: increases the risk of flea infestation.

Pregnancy: mosquitoes are attracted to pregnant women.

Skin ulcers: attract certain species of flies, which then lay their eggs at the ulcer site.

[Burns, 2004]

Complications of insect bites

What are the complications of insect bites?

Secondary bacterial infection may occur as a result of scratching or may be introduced at the time of the bite. It can present as impetigo, folliculitis, cellulitis, or lymphangitis [Burns, 2004].

Lyme disease (caused by infection with the bacterium Borrelia burgdorferi) is transmitted by the tick Ixodes ricinus.

Lyme disease is uncommon in the UK, but the incidence is rising annually. Approximately 694 cases were diagnosed in 2006 [HPA, 2006a; HPA, 2007].

Occupationally-acquired Lyme disease occurs in forestry workers, farmers, deer handlers, and gamekeepers. It should be notified to the Health and Safety Executive (HSE) [HPA, 2006a].

Areas where infection is acquired include Exmoor, the New Forest, the South Downs, parts of Wiltshire and Berkshire, Thetford Forest, the Lake District, the Yorkshire moors, and the Scottish Highlands.

Lyme disease is most commonly diagnosed during the summer (coinciding with tick activity), but cases are reported throughout the year.

There is an initial infection, characterized by a red rash which gradually expands from the site of the tick bite (erythema migrans).

If disseminated Lyme disease occurs, erythema migrans may occur at other sites, and other body systems may be affected (heart, nervous system, joints, eyes), with gradual progression over months to years. In the UK, disseminated Lyme disease most commonly affects the nervous system, with symptoms such as facial palsy, meningitis, and radiculopathy. Arthritis is a rare complication of UK-acquired infection but is more common in people who have been infected in North America or central Europe.

For further information see the Health Protection Agency (HPA) website and the CKS topic on Lyme disease.

West Nile virus: there have been no reported human cases in the UK. The species of mosquitoes that may transmit the infection (Culex spp.) are present in the UK, but are unlikely to be numerous enough to sustain transmission to humans. However, given the recent increases in West Nile virus activity elsewhere in the world, the Health Protection Agency (HPA) and Department of Health have, since the summer of 2001, been raising awareness of this virus amongst doctors [HPA, 2006b].

Clinicians are advised to consider West Nile virus as a differential diagnosis in people over 50 years old with a clinical picture of viral encephalitis or aseptic meningitis. In most people the infection is asymptomatic or causes a mild influenza-like illness.

Malaria: this is a tropical disease caused by infection of red blood cells by Plasmodium, a protozoan parasite which is transmitted to humans following a bite from its vector, the Anopheles mosquito.

Over 2000 cases of malaria are imported into the UK each year.

P. falciparum (which is potentially fatal) accounts for over half of these cases.

For more information, see the CKS topic on Malaria prophylaxis.

Complications of insect stings

What are the complications of insect stings?

Urticarial reaction may develop in some people several hours after the sting.

For more information see the CKS topic on Urticaria.

Fever and malaise may occur if the local reaction is severe or if bites are numerous.

Multiple bee or wasp stings may cause systemic toxic effects including hypotension, diarrhoea, vomiting, headache, generalized vasodilation, and shock. In children, this may be fatal [Burns, 2004].

A serum sickness-like reaction with urticaria, joint swelling, and arthralgia may occur very rarely 7–10 days after a sting [Reisman, 1994].

Anaphylaxis can occur after an insect sting, particularly from a bee or wasp [Burns, 2004].

The incidence of anaphylaxis due to insect stings in the general population is not reliably known, but has been estimated to be between 0.3–3% [Moffitt et al, 2004]. Every year in the UK there are 2–9 deaths due to anaphylaxis from bee or wasp stings [The Anaphylaxis Campaign, 2005].

Studies of fatalities following bee and wasp stings have shown the major cause of death to be respiratory tract obstruction from massive oedema and secretions [Burns, 2004].

A short interval between stings increases the risk of a systemic reaction to a later sting. With increasing intervals between stings, the risk of a systemic reaction decreases.

Adults who have had a previous severe systemic reaction to a sting have a 79% risk of having a subsequent systemic reaction. In people with a mild systemic reaction, the risk of subsequent systemic reactions is thought to be about 18% [Bilo et al, 2005].

After a large local reaction, 5–15% of people will go on to develop a systemic reaction when next stung [Bilo et al, 2005].

Beta-blockers may increase the severity of an anaphylactic reaction.

People allergic to wasp venom are rarely allergic to bee venom [Ewan, 1998].

Other rare complications of insect stings include neuritis, myasthenia gravis, cerebral infarction, Guillain–Barré syndrome, encephalitis, Reye-like syndrome, myocardial infarction, and cardiac arrhythmia [Moffitt, 2003].

Prognosis

What is the prognosis?

Most insect bite reactions resolve quickly (within hours), but occasionally they may persist for months.

Persistent reactions are particularly likely with tick bites, as persistent granulomatous papules or nodules may be provoked by retained mouthparts. However, most tick bites will heal within 3 weeks [Wilson and King, 2003; Micromedex, 2007].

Most insect stings produce a transient local reaction that lasts for several days and generally resolves without treatment [Moffitt et al, 2004].

Diagnosis and assessment

Diagnosis and assessment of insect bites and stings

Diagnosis - insect bite

How do I know my patient has an insect bite?

The diagnosis of insect bites or stings is often self-evident and made on the basis of known exposure, or it can be surmised from the distribution of lesions.

Irritation is an almost constant symptom, and rubbing and scratching may increase the inflammatory changes and eczematization.

Papular urticaria is a common presentation in children, especially those between 2 and 7 years old, and those with a history of atopic dermatitis. It is less common in adults.

Papular urticaria is caused by a sensitivity reaction to the bites of fleas, lice, bedbugs, gnats, mites, and other insects.

Lesions occur in the area of the bite, and may also occur at distant sites.

Lesions tend to be grouped on exposed areas, particularly the extensor surfaces of the extremities.

Lesions consist of groups or lines of intensely itchy indurated papules, which persist for up to 2 weeks.

Scratching may produce erosions and ulcerations.

Secondary impetigo or pyoderma is common.

Bullous reactions are common on the lower legs but may occur at other sites, particularly in children.

Fever or malaise may be present if the bites are numerous, or if there is a severe local reaction.

Typical presentations of different biting insects are shown in Table 1

Table 1 . Typical presentations of common insect bites.
Biting insect Presentation
Midges, mosquitoes, and gnats Bites usually cause small papular lesions. Weals and bullae (large blisters) may form in sensitized individuals.
Fleas — animal/human Bites may be grouped in lines or in irregular clusters. Bites usually cause papular urticaria in sensitized individuals. Occasionally bullae may occur. Cat and dog flea bites occur predominantly on the legs below the knee, but can occur on the forearm.
Horseflies Bites are often very painful, and urticaria, dizziness, weakness, wheezing, or angio-oedema may accompany the resulting cutaneous weal. Secondary infection is common.
Bedbugs Bites are painless, and there may be no symptoms if the individual has not previously been bitten. Sensitized people characteristically develop intensely irritating weals or papules surmounted by haemorrhagic puncta. Bites usually occur on the face, neck, hands, and arms, but may be generalized.
The Blandford fly (found in an arc running from East Anglia through Oxfordshire into Dorset) Bites occur most frequently on the legs and are very painful. The bites often produce a severe local reaction, with oedema and blistering, and may be accompanied by fever or pain in the joints.
Ticks Bites are not usually painful and there may only be a red papule at the bite site that may progress to local swelling and erythema. In some cases blistering, severe pruritus, and bruising develop.
Cheyletiella mites (frequently harboured by dogs and cats) Intensely itchy papules appear where the mites have fed on skin. There may be a tiny vesicle surmounting the papule, and older lesions may show necrosis. Bullous lesions may occur. The abdomen and thighs are frequently involved as a result of the animal sitting on its ower's lap.
Mites that occur in stored products (e.g. grain, flour, dried meat, cheese, and fruit) Bites cause intensely itchy, small pruritic papules, or papulovesicles on exposed parts of the body.
Adapted from: [Wilson and King, 2003; Burns, 2004]

Basis for recommendation

Basis for recommendation

This information is based on expert opinion in Rook's Textbook of Dermatology and in review articles [Millikan, 1993; Stibich and Schwartz, 2001; Burns, 2004; Stibich, 2005].

Diagnosis - insect sting

How do I know my patient has an insect sting?

The diagnosis of insect bites or stings is often self-evident and made on the basis of known exposure, or it can be surmised from the distribution of lesions.

Insect stings typically produce intense burning pain, followed by erythema and a small area (up to 1 cm) of oedema, which usually subsides within 4–6 hours.

Allergic reactions can be either local or systemic.

Large local reactions cause severe pain and marked local oedema that extends beyond the site of the sting, which evolves over several hours, and which lasts up to 7 days. Such oedema is not dangerous unless it affects the airway. Large local allergic reactions occur in 10–15% of adults.

Generalized (systemic) reactions usually occur within a few minutes of the sting and features may include:

Rhinitis and conjunctivitis

Abdominal cramps and pain, nausea and vomiting, and diarrhoea

Erythema

Generalized pruritus followed by urticaria

Facial or generalized angio-oedema

A sense of impending doom

Tachycardia

Hypotension (causing light-headedness, giddiness, and fainting)

Difficulty in breathing due to severe bronchospasm or throat swelling

Collapse and unconsciousness

These features may occur separately or in combination, and in varying degrees of severity.

Basis for recommendation

Basis for recommendation

This information is based on expert opinion in review articles [Ewan, 1998; Moffitt, 2003; Burns, 2004; Steen et al, 2005].

The incidence of large local reactions is based on a practice parameter on stinging insect hypersensitivity [Moffitt et al, 2004].

Differential diagnosis

What else might it be?

Cellulitis — large local reactions to an insect bite may occasionally be confused with cellulitis. The presence of ascending lymphangitis and lymphadenopathy suggest an infectious cause.

Chickenpox

Urticaria

Contact dermatitis

Scabies

Pubic lice

Basis for recommendation

Basis for recommendation

This information is based on expert opinion in review articles [Millikan, 1993; Reisman, 1994].

Identifying the source

How can I identify the potential source of an insect bite or sting?

A careful history may reveal the origin of the bite or sting. Factors to consider when taking a history include:

Domestic pets: not only in the person's home but also those in homes frequently visited, as these are often the source of persistent flea bites.

Recent house move: a history of recently moving to a new house (even if it has remained empty for some time) suggests that the bites may be from fleas, which can survive for a few months in the absence of their natural host.

Living environment: infestation with the human flea occurs mainly in overcrowded communities with low standards of hygiene.

Presence of nests or nest boxes on or near the house: may cause household infestations with bird fleas.

Old houses, poultry houses, bird nests, furniture, and upholstery: may harbour bedbugs, which may travel great distances to reach a suitable host.

Occupation: bee keepers get bee stings; forestry workers may get tick bites; people who handle stored products, such as dockworkers or warehouse workers, are most at risk from mite dermatitis, but shopkeepers and domestic workers may also occasionally be affected.

Recent travel: the bite may be due to a foreign insect.

Confirm the presence of an infestation by looking for:

Fleas and dried masses of flea faeces in the fur of an affected animal.

Fleas in the animal's bedding (flea eggs and faeces have a 'pepper and salt' appearance).

Areas of crusting or alopecia in the animal's fur (common in dogs), and scratching or excessive grooming (common in cats) are a sign of flea infestation.

Excessive dandruff, 'walking dandruff' especially on the back of a cat or dog, is a sign of infestation with cheyletiella mites.

Blood spotting on bed linen and a heavy, unpleasant, almond smell indicates activity of bedbugs.

Where it is difficult to confirm the presence of an infestation, seek specialist advice from a veterinary surgeon or a pest control agency.

Give advice regarding eliminating the infestation:

Flea infestations:

Treat the pet, its bedding, and household carpets and soft furnishings with an insecticide.

Rugs and furniture should be thoroughly vacuumed.

Limit contact with other pets.

Cheyletiella mite:

Seek local veterinary advice as aggressive treatment is needed.

Bedbugs:

Contact a reputable pest control company, so that thorough treatment with a residual insecticidal spray or powder can be carried out. It may be necessary to treat on more than one occasion to completely eradicate bedbugs.

Basis for recommendation

Basis for recommendation

These recommendations are mainly based on what CKS considers to be current good practice. The recommendation regarding confirming and eliminating the infestation is based on expert opinion from the medical literature [Parish and Schwartzman, 1993; Hunter et al, 2002; Burns, 2004; Royal Pharmaceutical Society, 2005].

Assessments

What assessments do I need to make?

Assess the severity of symptoms.

Small local reactions present with localized pain, swelling, and erythema at the site of the bite or sting.

Large local reactions present with severe pain, and oedema that extends beyond the site of the sting or bite.

Multiple bee or wasp stings may cause systemic toxicity (including hypotension, diarrhoea, vomiting, headache, generalized vasodilation, and shock) which requires urgent action. It can be fatal, particularly in children.

Anaphylaxis can occur after an insect sting (usually within minutes), particularly from a bee or wasp, and requires urgent action. Anaphylaxis after an insect bite is rare.

Late-onset reactions to stings can occur (after several hours), which present as urticarial reactions or serum sickness-like reactions with urticaria, joint swelling, and arthralgia.

Look for signs of secondary infection.

This is a common complication of insect bites, and may appear as impetigo, cellulitis, or lymphangitis.

Signs that suggest a secondary infection include:

The presence of pus.

Increasing erythema, oedema, or tenderness beyond the anticipated pattern of response.

Regional lymphadenopathy — but this can also occur in the absence of infection, as a response to the inflammatory reaction produced by a bite.

Lymphangitis — a definite sign of infection, usually with Group A beta-haemolytic streptococci.

Basis for recommendation

Basis for recommendation

These recommendations are based on expert opinion from the medical literature [Kemp, 1998; Burns, 2004; Micromedex, 2007].

Management

Management

Scenario: Small local reactions : covers the management of someone with a small local reaction to an insect bite or sting.

Scenario: Large local reactions : covers the management of someone with a large local reaction to an insect bite or sting.

Scenario: Systemic reactions : covers the management of someone who has had a systemic reaction to an insect bite or sting. It does not discuss the management of anaphylaxis. See the CKS topic on Angio-oedema and anaphylaxis for a detailed discussion on how to manage anaphylaxis.

Scenario: Infection : covers the management of someone with an infected bite or sting.

Scenario: Tick bite : covers the management of someone with a tick bite.

Scenario: Prevention : covers advice regarding the prevention of insect bites and stings.

Scenario: Small local reactions

Scenario: Small local reactions

1months3060monthsBoth

Self care advice for bite or sting

What self care advice should I give for someone with an insect bite or sting?

Small local reactions to insect bites or stings present with localized pain, swelling, and erythema at the site of the bite or sting. Most can be managed symptomatically.

If a person has been stung and the stinger is still in place:

Remove it as soon as possible by flicking or scraping with a fingernail, piece of card, or knife blade.

Never squeeze the stinger or use tweezers, as this will cause more venom to go into the skin.

Remove ticks as soon as possible.

Wash the area of the bite or sting with soap and water.

Apply ice to reduce swelling, if present.

Do not scratch, as this will cause the site to swell and itch more, and increase the chance of infection.

If there are signs of a severe allergic reaction (generalized symptoms, breathing difficulties, and/or hypotension) seek urgent medical help.

Bites from fleas, mites, and bedbugs may be due to an infestation. The source of the infestation should be confirmed and eliminated (see Identifying the source for more information).

Basis for recommendation

Basis for recommendation

These recommendations are based on pragmatic advice and reviews by experts from the medical literature [Reisman, 1994; Kemp, 1998; Moffitt et al, 2004; Steen et al, 2005].

Honey bee stingers are barbed and usually remain in the skin after a sting. They need to be removed as quickly as possible, as the injection mechanism continues to operate even after separation from the insect.

Ticks need to be removed as quickly as possible, to reduce the risk of tick borne infection such as Lyme disease.

Drug treatments for small local reactions

What drug treatments can I recommend for small local reactions to insect bites or stings?

Treat local pain and oedema with cold compresses and oral analgesics (e.g. paracetamol or ibuprofen).

Treat local itching with topical crotamiton. Alternatively, consider using a mild potency topical corticosteroid (e.g. hydrocortisone 1%).

Apply crotamiton 2–3 times a day. For children under 3 years old, apply crotamiton once a day only.

Apply topical hydrocortisone sparingly to the affected area once or twice a day for no longer than 7 days.

Consider an oral sedating antihistamine at night if the itch is interfering with sleep.

The following treatments are not recommended for the treatment of insect bites or stings:

Topical combination products containing a topical corticosteroid plus crotamiton

Topical antihistamines

Calamine lotion

Vinegar

Bicarbonate of soda

Basis for recommendation

Basis for recommendation

These recommendations are based on expert opinion from the medical literature [Kemp, 1998; Burns, 2004; Moffitt et al, 2004; Steen et al, 2005; Micromedex, 2007].

Topical treatments:

Crotamiton cream or lotion has soothing qualities and may help to relieve itch, although no controlled studies have been published that assess its efficacy. It is licensed for the relief of itching and skin irritation caused by insect bites and stings.

CKS could find no trial evidence for topical hydrocortisone. However, it is licensed for the treatment of insect bite reactions, and is widely recommended to reduce inflammation and itching after an insect bite or sting [BNF 52, 2006].

The recommendation for the application of topical crotamiton and hydrocortisone are taken from the British National Formulary [BNF 52, 2006].

Oral antihistamines:

CKS found limited evidence that oral antihistamines are effective in treating pruritus.

Results from a review of 16 randomized controlled trials and other studies (n = 803) suggest that neither first nor second generation antihistamines offer relief from itch in conditions such as atopic dermatitis [Klein and Clark, 1999].

Several small, poorly designed trials have found that loratadine and cetirizine reduce cutaneous reactions and pruritus when given for mosquito bites. However, larger studies are needed to confirm this [Karppinen et al, 2000; Karppinen et al, 2002].

Treatments not recommended:

It is best to prescribe the components of topical combination products containing corticosteroids separately rather than as a combined preparation, as this minimizes exposure to topical corticosteroids and their potential adverse effects.

Topical antihistamines are of limited efficacy and may cause sensitization [BNF 52, 2006].

Calamine lotion generally soothes itch, although the dried residue can exacerbate itch in some people. Calamine preparations are of little value for the treatment of insect bites and stings [BNF 52, 2006].

Vinegar has traditionally been used to treat wasp stings as their venom is alkaline. Bicarbonate of soda has also been used to treat bee stings as their sting venom is acidic. Neutralizing a bee sting or wasp sting is unlikely to be effective or practically possible as:

The venom from wasps and bees (5–50 micrograms of fluid) is injected under the skin and after a few minutes spreads deep into the tissues. The applications of an unknown strength of vinegar or bicarbonate of soda onto the skin surface is unlikely to neutralize the venom [Glaser, 2007].

Follow up and referral

When should I follow-up or refer a person with a small local reaction?

Follow-up or referral is usually not necessary for anyone with a small local reaction to an insect bite or sting.

Admission may be required for observation when mild symptoms progress to a severe reaction (uncommon).

The decision to admit will depend upon the type of reaction, social circumstances, and access to local medical facilities. Exercise clinical judgement in these circumstances.

Basis for recommendation

Basis for recommendation

This recommendation is based on what CKS considers to be current good practice.

Scenario: Large local reactions

Scenario: Large local reactions

1months3060monthsBoth

Large local reactions to bite or sting

How do I manage large local reactions to an insect bite or sting?

Large local reactions present with severe pain, and oedema that extends beyond the site of the sting or bite. Most can be managed symptomatically.

Treat pain with an oral analgesic (e.g. paracetamol or ibuprofen).

Treat large local allergic reactions with a short course of an oral antihistamine.

Offer a non-sedating antihistamine to control daytime symptoms.

Consider giving an additional sedating antihistamine at night if the itch is interfering with sleep.

Consider using a short course of an oral corticosteroid (e.g. prednisolone for 3–5 days) if local swelling is severe.

For adults use prednisolone 40 mg once a day for 3–5 days depending on the severity of the reaction.

For children use prednisolone 1–2 mg/kg once a day for 3–5 days.

If the airway is affected, treat urgently as anaphylaxis — see the CKS topic on Angio-oedema and anaphylaxis for more information.

Advise the person or their carer to seek urgent medical review if symptoms of systemic toxicity develop.

Basis for recommendation

Basis for recommendation

These recommendations are based on expert opinion from the medical literature [Reisman, 1994; Kemp, 1998; DTB, 2002; Moffitt et al, 2004; Steen et al, 2005].

Most people with large local reactions need only symptomatic care. However, if oedema affects the airway, this is a medical emergency and needs immediate treatment and admission to hospital [Ewan, 1998].

Oral antihistamines:

No published randomized controlled trials have assessed the efficacy of oral antihistamines in the treatment of acute urticaria, although they are widely recognized as the mainstay of treatment.

In chronic urticaria, second-generation antihistamines have been shown to be more effective than placebo in controlling itch and the appearance of weals, whilst reducing sleeplessness and lessening interference with daily activities.

Oral corticosteroids:

No controlled studies have assessed the use of oral corticosteroids in the treatment of large local reactions to insect stings or bites. However, if there is a severe, extensive local reaction, experts recommend a short course of high-dose oral corticosteroids to control symptoms [Reisman, 1994; Moffitt et al, 2004; Steen et al, 2005].

In view of the lack of prospective studies of oral corticosteroids for systemic or large local reactions to insect bites or stings, CKS recommends that a 3–5 day course of oral prednisolone is given, in the doses used for an acute exacerbation of asthma [SIGN and BTS, 2005].

Referral

When should I refer a person with a large local reaction?

Admission may be required for observation when mild symptoms progress to a severe reaction (uncommon).

The decision to admit will depend upon the type of reaction, social circumstances, and access to local medical facilities. Exercise clinical judgement in these circumstances.

The Anaphylaxis Campaign recommends referral to an allergy clinic if there is a large local skin reaction, with redness and swelling over 10 cm in diameter. However clinicians should check the referral policy of their local allergy clinic as this may vary.

Seek specialist advice from an allergy clinic or immunologist regarding local recommendations for interim management of anyone waiting to be seen by the allergy clinic.

Allergy clinic treatments

Treatments that may be offered by an allergy clinic

Treatments that may be offered by an allergy clinic include:

Self-injectable adrenaline. This is usually prescribed to people at known risk of systemic reactions to bee or wasp venom, together with a written treatment plan. The patient (and relatives) are usually taught in secondary care how and when to use the adrenaline self-injector.

Immunotherapy (desensitization). This is available at a few centres in the UK.

The diagnosis of wasp or bee sting allergy can be confirmed at an allergy clinic. Any potential risk can then be discussed [The Anaphylaxis Campaign, 2005].

Immunotherapy consists of a weekly injection for 8 weeks. If by that time a dose of two stings has been reached, then monthly injections are continued for two to three years or longer. Some specialised clinics use various modifications of this injection treatment.

The indications for desensitization in Britain are conservative, because of the high incidence of spontaneous improvement, and the potential adverse effects of desensitization treatment [Ewan, 1998].

Immunotherapy continues to be available at specialized centres because it is effective in cases of life-threatening venom hypersensitivity.

All patients receiving immunotherapy have to wait one hour after each injection in case it causes a reaction.

Basis for recommendation

Basis for recommendation

These recommendations are based on expert opinion and pragmatic advice [The Anaphylaxis Campaign, 2005].

Scenario: Systemic reactions

Scenario: Systemic reactions

1months3060monthsBoth

Systemic reactions to bite or sting

How do I manage systemic reactions to an insect bite or sting?

If a severe systemic reaction occurs, such as wheezing or other signs of respiratory distress, or hypotension:

Treat urgently as for anaphylaxis and admit to hospital (see the CKS topic Angio-oedema and anaphylaxis).

If there are symptoms of systemic toxicity that suggest impending anaphylaxis (e.g. abdominal pain, vomiting, rhinitis and conjunctivitis, or a sense of impending doom):

Treat as for anaphylaxis and admit to hospital (see the CKS topic Angio-oedema and anaphylaxis).

If generalized urticaria occurs, but the person is otherwise well:

Give an oral antihistamine and an oral corticosteroid.

Offer a non-sedating antihistamine to control daytime symptoms.

Consider giving an additional sedating antihistamine at night if the itch is interfering with sleep.

In adults, give prednisolone 40 mg once a day, and in children give 1–2 mg/kg body weight once a day.

Continue prednisolone for 3–5 days, depending on the severity of the reaction.

Advise the person to seek urgent medical help if the rash worsens, swelling develops which involves the mouth or throat, or wheeze or breathing difficulty occurs.

Advise the person to seek urgent medical review if symptoms of systemic toxicity develop.

Basis for recommendation

Basis for recommendation

The basis for this recommendation is expert opinion from the published literature [Spickett, Personal Communication, 2003; Burns, 2004; Moffitt et al, 2004].

Oral antihistamines:

No published randomized controlled trials have assessed the efficacy of oral antihistamines in the treatment of acute urticaria, although they are widely recognized as the mainstay of treatment.

In chronic urticaria, second-generation antihistamines have been shown to be more effective than placebo in controlling itch and the appearance of weals, whilst reducing sleeplessness and lessening interference with daily activities.

Sedating antihistamines are not recommended for daytime use because the drowsiness they cause can affect a person's ability to drive or perform other skilled tasks [Grattan et al, 2001; Zuberbier et al, 2006]. However, the addition of a sedating antihistamine at night to a non-sedating (daytime) antihistamine may help people unable to sleep due to itching, and is considered to be safe [Grattan et al, 2001].

Oral corticosteroids:

For people with severe acute urticaria, experts recommend a short course of high-dose oral corticosteroids [Reisman, 1994; Moffitt et al, 2004; Steen et al, 2005].

In view of the lack of studies of oral corticosteroids for systemic reactions or large local reactions to insect bites or stings, CKS recommends that a 3–5 day course of oral prednisolone is used, in the doses used for an acute exacerbation of asthma [SIGN and BTS, 2005].

When to refer or seek specialist advice

When should I refer or seek specialist advice?

Admit all patients with anaphylaxis, after immediate emergency management (see the CKS topic Angio-oedema and anaphylaxis).

If mild symptoms appear to be worsening then admission may be required for observation (uncommon).

The decision to admit will depend upon on the type of reaction, social circumstances, and access to local medical facilities. Exercise clinical judgement in these circumstances.

Consider referral to an allergy clinic if an insect sting or bite has caused generalized symptoms.

The Anaphylaxis Campaign recommends referral to an allergy clinic if there is a large local skin reaction, with redness and swelling over 10 cm in diameter. However clinicians should check the referral policy of their local allergy clinic as this may vary.

Seek specialist advice from an allergy clinic or immunologist regarding local recommendations for interim management of anyone waiting to be seen by the allergy clinic.

Allergy clinic treatments

Treatments that may be offered by an allergy clinic

Treatments that may be offered by an allergy clinic include:

Self-injectable adrenaline. This is usually prescribed to people at known risk of systemic reactions to bee or wasp venom, together with a written treatment plan. The patient (and relatives) are usually taught in secondary care how and when to use the adrenaline self-injector.

Immunotherapy (desensitization). This is available at a few centres in the UK.

The diagnosis of wasp or bee sting allergy can be confirmed at an allergy clinic. Any potential risk can then be discussed [The Anaphylaxis Campaign, 2005].

Immunotherapy consists of a weekly injection for 8 weeks. If by that time a dose of two stings has been reached, then monthly injections are continued for two to three years or longer. Some specialised clinics use various modifications of this injection treatment.

The indications for desensitization in Britain are conservative, because of the high incidence of spontaneous improvement, and the potential adverse effects of desensitization treatment [Ewan, 1998].

Immunotherapy continues to be available at specialized centres because it is effective in cases of life-threatening venom hypersensitivity.

All patients receiving immunotherapy have to wait one hour after each injection in case it causes a reaction.

Basis for recommendation

Basis for recommendation

These recommendations are based on expert opinion and pragmatic advice [The Anaphylaxis Campaign, 2005].

Scenario: Infection

Scenario: Infected sting or bite

1months3060monthsBoth

Managing an infected bite or sting

How do I manage an infected insect bite or sting?

Treat empirically with oral antibiotics for 7 days:

Oral flucloxacillin is recommended for empirical treatment of staphylococcal and streptococcal skin infections.

An oral macrolide (erythromycin, or clarithromycin if erythromycin is not tolerated) is an alternative for people with penicillin-allergy.

If treatment is not effective, seek specialist advice regarding further management.

Basis for recommendation

Basis for recommendation

These recommendations are pragmatic advice, based on the most likely causative organism (Staphylococcus aureus or streptococci). We found no randomized controlled trials that studied the effectiveness of antibiotic treatment (or the length of antibiotic course needed) for insect bites or stings.

Flucloxacillin has a narrow spectrum of activity, and is active against most susceptible Gram-positive cocci, including beta-lactamase producing staphylococci and streptococci. However, it is not active against MRSA (meticillin-resistant S. aureus), which is increasingly prevalent in the UK. It penetrates well into most tissues, so is suitable for skin and soft tissue infections [Finch et al, 2003].

Erythromycin and clarithromycin have a broad spectrum of activity and are active against most sensitive Gram positive cocci (including staphylococci and streptococci) and some Gram negative cocci and anaerobes [Finch et al, 2003].

Clarithromycin may be used in people who are known not to tolerate erythromycin, as it has fewer gastrointestinal adverse effects [Finch et al, 2003]. However, it is markedly more expensive than erythromycin.

Azithromycin (and other macrolides) are not recommended for empirical treatment as there are concerns about increasing resistance [McNulty, Personal Communication, 2006].

Scenario: Tick bite

Scenario: Tick bite

1months3060monthsBoth

Managing a tick bite

How do I manage a tick bite?

Remove the tick quickly with fine-tipped tweezers, and protect bare hands with a tissue or gloves to avoid contact with tick fluids.

Grab the tick close to the skin.

Gently pull straight up until all parts of the tick are removed.

After removing the tick, wash your hands with soap and water.

Clean the tick bite with an antiseptic such as iodine scrub, or soap and water.

Do not twist or jerk the tick as it is being removed, as this may cause the mouthparts to break off and remain in the skin.

Do not try to make the tick back out by using petroleum jelly, alcohol, or a lit match, as these are ineffective.

Do not routinely offer antimicrobial prophylaxis or carry out serological tests for Lyme disease, but advise that if a rash appears at the site of the bite (erythema migrans) or a fever develops, the person should promptly seek medical advice.

For further information see the CKS topic on Lyme disease.

Basis for recommendation

Basis for recommendation

These recommendations are based on advice from the Centre for Disease Control in the USA and from the Health Protection Agency [CDC, 2005; HPA, 2006c].

Scenario: Prevention

Scenario: Preventing insect bites and stings

1months3060monthsBoth

Advice on prevention

What advice can I give to people to prevent insect bites and stings?

Advise the person to:

Take sensible precautions, especially if they have had a bad reaction to a sting or bite in the past:

Cover exposed skin where possible (e.g. wear long sleeves or trousers).

Wear shoes when out of doors.

Avoid using products with strong perfumes (e.g. soaps, shampoos, and deodorants) as these attract insects.

Avoid flowering plants, outdoor areas where food is served, rubbish, or compost areas.

Destroy insect nests (e.g. wasp nests) in or near the person's house or garden. The local council or a pest control expert may need to remove the nest.

Avoid tick-infested areas if possible, however if the person is in a tick-infested area they should:

Wear long sleeved shirts and trousers tucked into socks (light coloured fabrics are useful as it is easier to see ticks against a light background).

Walk in the centre of paths to avoid contact with vegetation.

Check that ticks are not brought home on clothes.

Inspect skin frequently and remove any attached ticks.

Ensure that children's head, neck and scalp areas are checked.

To reduce the risk of insect bites apply an insect repellent to exposed areas. Repellents that contain DEET (diethyl-toluamide) are usually considered the most effective.

See Choice of insect repellent for more information.

Basis for recommendation

Basis for recommendation

These recommendations are based on advice from the medical literature [Moffitt, 2003; CDC, 2005; The Anaphylaxis Campaign, 2005; HPA, 2007].

Choice of insect repellent

Which insect repellent should I recommend?

Use insect repellents that contain DEET (diethyl-toluamide) as they are more effective than other insect repellents.

CKS recommends formulations that contain 50% DEET.

These have the longest duration of protection (up to 12 hours).

There is no evidence that any group (including pregnant women and small children) is at increased risk from using 50% DEET.

Using DEET preparations

Using DEET preparations

DEET applications can damage some plastic watch straps, watch 'glass', and plastic jewellery; these items should not be allowed to come into contact with DEET.

When both sunscreen and DEET are required, DEET should be applied after application of sunscreen.

DEET reduces the efficacy of sunblock, but sunscreens do not reduce the effectiveness of DEET.

Basis for recommendation

Basis for recommendation

These recommendations are based on expert opinion from Guidelines for Malaria prevention published by the Health Protection Agency [Chiodini et al, 2007], and expert reviews from the medical literature.

Lower concentrations of DEET (diethyl-toluamide) have shorter durations of protection and require more frequent applications. The duration of protection for DEET is:

1 to 3 hours for 20%.

Up to 6 hours for 30%.

Up to 12 hours for 50%.

There is no further increase in duration of protection beyond a concentration of 50%.

For malaria prevention concentrations of DEET below 20% are considered inappropriate in any circumstances [Chiodini et al, 2007].

There is no evidence that any group (including pregnant women and small children) is at risk from using 50% DEET.

Other commercially available products do not afford the same amount of protection as 50% DEET:

Lemon eucalyptus oil gives about the same amount of protection as afforded by 15% DEET.

Picaridin is reported to have repellent properties comparable to 20% DEET.

Citronella oil provides short-lived protection (20–30 minutes).

There is no evidence that garlic, thiamine (vitamin B1), bath oils, or tea tree oil are capable of repelling mosquitoes.

[Roberts and Reigart, 2004; CCDR, 2005; Chiodini et al, 2007]

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).

Antihistamines

Choice for pruritus

Which antihistamine should I use to treat pruritus?

For pruritus, offer a sedating antihistamine e.g. chlorphenamine or hydroxyzine, to be taken at bedtime.

Basis for recommendation

There is very limited evidence that antihistamines are effective in treating pruritus.

Chlorphenamine and hydroxyzine are sedating oral antihistamines. They probably provide a reprieve from nocturnal scratching by causing sedation, helping to break the itch-scratch-itch cycle:

Hydroxyzine is specifically licensed for pruritus.

Chlorphenamine (chlorphenamine) is inexpensive, and is an effective sedating antihistamine of intermediate duration.

Alimemazine (licensed for pruritus) and promethazine (not licensed for pruritus) have pronounced sedative effects. Hangover effects are common and these drugs are therefore not recommended.

A review of 16 randomized controlled trials and other studies (n = 803) suggests that neither first nor second generation antihistamines offer relief from itch in conditions such as atopic dermatitis [Klein and Clark, 1999].

Several small, poorly designed trials have found that loratadine and cetirizine reduce cutaneous reactions and pruritus when given for mosquito bites. However, larger studies are needed to confirm this [Karppinen et al, 2000; Karppinen et al, 2002].

Antihistamines for urticaria

Which antihistamine should I use to treat urticaria?

Cetirizine, fexofenadine, or loratadine (once-daily non-sedating antihistamines) are recommended for the treatment of urticaria.

If an additional sedating antihistamine is needed for night-time use, if the itch is interfering with sleep, chlorphenamine or hydroxyzine are recommended.

Non-sedating antihistamines are routinely increased beyond the recommended licensed dose in secondary care to control symptoms. It is not advisable to increase above the maximum licensed dose unless the healthcare professional has experience in doing so, or before seeking specialist advice.

Basis for recommendation

Antihistamines (H1-receptor blockers) are the only drugs licensed for use in urticaria.

Although the efficacy of antihistamines has only been demonstrated for chronic urticaria, there is a consensus that they are also effective for acute urticaria [Grattan et al, 2001; Zuberbier et al, 2006]:

Histamine is one of the primary mediators of urticaria.

In people with chronic urticaria, randomized controlled trials of non-sedating antihistamines have demonstrated improvements in symptoms of itch, weal formation, frequency of exacerbations, and quality of life [Belaich et al, 1990; Breneman et al, 1995; Kaplan et al, 2005; Zuberbier et al, 2006].

Non-sedating antihistamines should therefore be used initially to control daytime symptoms.

Sedating antihistamines are not recommended for daytime use because the drowsiness they cause can affect a person's ability to drive or perform other skilled tasks [Grattan et al, 2001; Zuberbier et al, 2006]. However, the addition of a sedating antihistamine at night to a non-sedating (daytime) antihistamine may help people who are unable to sleep due to itching, and is considered to be safe [Grattan et al, 2001].

Desloratadine (a metabolite of loratadine) and levocetirizine (an isomer of cetirizine) are more recently marketed products, but there is little evidence to confirm whether they confer any additional benefit over the more established non-sedating antihistamines [MeReC, 2004].

Mizolastine has been implicated in causing an abnormal prolongation of the QT interval and is therefore not recommended as a first-line treatment.

Acrivastine is not recommended as it has a short half-life and needs to be taken three times a day.

Adverse effects of antihistamines

What are the adverse effects of antihistamines?

Sedating antihistamines cause sedation in 10–50% of people, which can persist into the next day [DTB, 2002].

Most non-sedating antihistamines have the potential to cause sedation, especially at higher doses. Advise people taking non-sedating antihistamines that they may cause sedation, and that the sedative effects are enhanced when combined with alcohol.

Choice in pregnancy

Which antihistamine can I prescribe during pregnancy?

Where possible, oral antihistamines should be avoided during pregnancy, especially during the first trimester.

If an oral antihistamine is required to control urticaria or pruritus during pregnancy, chlorphenamine is the antihistamine of choice.

Topical corticosteroids

Adverse effects

What are the adverse effects of topical corticosteroids?

Topical corticosteroids are associated with localized effects, such as skin atrophy and exacerbation of skin infections (e.g. fungal infection):

The risk of adverse effects increases with the potency of the topical corticosteroid, duration of use, and area of application (e.g. thin skin on the genitalia). Adverse effects are most likely with potent or super-potent topical corticosteroids when used in large quantities for prolonged periods.

Mildly and moderately potent topical corticosteroids used for short periods are rarely associated with adverse effects.

Skin atrophy is much more likely with potent and very potent topical corticosteroids.

There is little risk of skin thinning with mildly to moderately potent topical corticosteroids when used for up to 4 weeks.

Contact allergy to topical corticosteroids has also been reported (4–5%). The allergy is normally to preservatives in the preparation (more likely with creams) or, more rarely, to the corticosteroid itself.

Note: systemic effects, such as hypophyseal-pituitary-adrenal (HPA) suppression which may lead to growth retardation, are extremely rare. HPA has been observed following prolonged application of potent steroids to large areas of skin.

[MeReC, 1999; DTB, 2003]

Oral corticosteroids

Oral corticosteroids

Adverse effects are uncommon with occasional, short courses of oral corticosteroids.

If frequent courses of oral corticosteroids are needed, the following monitoring is recommended:

People taking frequent courses of oral corticosteroids require specialist supervision.

Blood pressure: monitor regularly and treat if necessary.

Diabetes mellitus: screen regularly and treat if necessary.

Osteoporosis: see the CKS topic on Osteoporosis - prevention of fragility fractures for details about when to prescribe long-acting bisphosphonate therapy.

Growth suppression: record height of children regularly and accurately.

Cataracts: screen children periodically.

Children who are on frequent courses of oral corticosteroids should have regular checks for signs of adrenal suppression, with referral to a paediatrician who can arrange synacthen testing where appropriate.

Flucloxacillin

Contraindications

Who should avoid taking flucloxacillin?

Anyone with a history of hypersensitivity to beta-lactam antibiotics (e.g. penicillins, cephalosporins) or excipients.

Anyone with a previous history of flucloxacillin-associated jaundice/hepatic dysfunction.

[ABPI Medicines Compendium, 2008]

Adverse effects

What are the adverse effects of flucloxacillin?

Diarrhoea is a common adverse effect of flucloxacillin.

Cholestatic jaundice and hepatitis may occur (very rarely) up to several weeks after treatment with flucloxacillin has been stopped. Administration for more than 2 weeks, and increasing age, are risk factors [CSM, 2004].

Allergic reactions which cause rashes and anaphylaxis can occur in 1–10% of people treated with penicillins [BNF 52, 2006].

Macrolides

Contraindications

Who should avoid taking macrolides?

People taking astemizole, pimozide, ergotamine, or dihydroergotamine should avoid taking erythromycin [BNF 52, 2006].

Adverse effects

What are the adverse effects of macrolides?

Erythromycin commonly causes gastrointestinal adverse effects, especially at higher doses. If gastrointestinal adverse effects are known to occur, consider prescribing clarithromycin instead.

Cardiac arrhythmias have been very rarely reported in people taking erythromycin or clarithromycin.

[ABPI Medicines Compendium, 2002]

Evidence

Evidence

Search strategy

Scope of search

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

Search dates

2007 - October 2011

Key search terms

Various combinations of searches were carried out. The terms listed below are the core search terms that were used for Medline.

exp "Insect Bites and Stings"/

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)
Sources of guidelines

National Institute for Health and Care Excellence (NICE)

Scottish Intercollegiate Guidelines Network (SIGN)

NICE Evidence

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

Royal Australian College of General Practitioners

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)

Driver and Vehicle Licensing Agency

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)

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

British National Formulary (BNF)

electronic Medicines Compendium (eMC)

European Medicines Agency (EMEA)

LactMed

Medicines and Healthcare products Regulatory Agency (MHRA)

REPROTOX

Scottish Medicines Consortium

Stockley's Drug Interactions

TERIS

TOXBASE

Micromedex

UK Medicines Information

References

ABPI Medicines Compendium (2002) Summary of product characteristics for Erythrocin 500. Electronic Medicines CompendiumDatapharm Communications Ltd. www.medicines.org.uk [Free Full-text]

ABPI Medicines Compendium (2008) Summary of product characteristics for Floxapen capsules 500mg. Electronic Medicines CompendiumDatapharm Communications Ltd. www.medicines.org.uk [Free Full-text]

Belaich, S., Bruttmann, G., Degreef, H. et al. (1990) Comparative effects of loratadine and terfenadine in the treatment of chronic idiopathic urticaria. Annals of Allergy 64(2 Pt 2), 191-194. [Abstract]

Bilo, B.M., Rueff, F., Mosbech, H. et al. (2005) Diagnosis of Hymenoptera venom allergy. Allergy 60(11), 1339-1349. [Abstract]

BNF 52 (2006) British National Formulary. 52nd edn. London: British Medical Association and Royal Pharmaceutical Society of Great Britain.

Breneman, D., Bronsky, E.A., Bruce, S. et al. (1995) Cetirizine and astemizole therapy for chronic idiopathic urticaria: a double-blind, placebo-controlled, comparative trial. Journal of the American Academy of Dermatology 33(2 Pt 1), 192-198. [Abstract]

Burns, D.A. (2004) Diseases caused by arthropods and other noxious animals. In: Burns, T., Breathnach, S., Cox, N. and Griffiths, C. (Eds.) Rook's textbook of dermatology. 7th edn. Oxford: Blackwell Science. 33.1-33.63.

CCDR (2005) Statement on personal protective measures to prevent arthropod bites. Canada Communicable Disease Report 31(ACS-4), 1-20.

CDC (2005) Tick tips. Centers for Disease Control and Prevention. www.cdc.gov

Chiodini, P., Hill, D., Lalloo, D. et al. (2007) Guidelines for malaria prevention in travellers from the United Kingdom. Health Protection Agency. www.hpa.org.uk [Free Full-text]

CSM (2004) Reminder: flucloxacillin and serious hepatic disorders. Current Problems in Pharmacovigilance 30(Oct), 9. [Free Full-text]

CSM (2005) Updated advice on the safety of selective COX-2 inhibitors. Committee on Safety of Medicines. www.mhra.gov.uk [Free Full-text]

DTB (2002) Oral antihistamines for allergic disorders. Drug & Therapeutics Bulletin 40(8), 59-62. [Abstract]

DTB (2003) Topical steroids for atopic dermatitis in primary care. Drug & Therapeutics Bulletin 41(1), 5-8. [Abstract]

Ewan, P.W. (1998) ABC of allergies: venom allergy. British Medical Journal 316(7141), 1365-1368. [Free Full-text]

Finch, R.G, Greenwood, D, Norrby, S.R. and Whitley, R.J. (2003) Antibiotic and chemotherapy: anti-infective agents and their use in therapy. 8th edn. London: Churchill Livingstone.

Glaser, D. (2007) Are wasp and bee stings alkali or acid and does neutralising their pH give sting relief? Insect Stings. www.insectstings.co.uk

Grattan, C., Powell, S., Humphreys, F. and British Association of Dermatologists (2001) Management and diagnostic guidelines for urticaria and angio-oedema. British Journal of Dermatology 144(4), 708-714. [Abstract]

HPA (2006a) Epidemiology of Lyme borreliosis. Health Protection Agency. www.hpa.org.uk [Free Full-text]

HPA (2006b) West Nile virus. Health Protection Agency. www.hpa.org.uk [Free Full-text]

HPA (2006c) Frequently asked questions on Lyme borreliosis. Health Protection Agency. www.hpa.org.uk [Free Full-text]

HPA (2007) Taking a walk on the wild side? Be tick aware says the Health Protection Agency. Health Protection Agency. www.hpa.org.uk

Hunter, J.A.A, Savin, J.A. and Dahl, M.V. (Eds.) (2002) Infestations. In: Clinical dermatology. 3rd edn. Oxford: Blackwell Science.

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