• Most insect bites and stings result in small, local reactions that can be managed symptomatically.
• Assess the severity of symptoms and assess for infection.
• Remove any stinger as soon as possible, if present.
• Treat small local reactions with:
• Cold compresses, oral analgesics (e.g. paracetamol or ibuprofen), topical crotamiton, topical hydrocortisone, or oral antihistamines.
• Treat large local reactions with:
• A short course of an oral antihistamine and oral analgesics.
• A short course of an oral steroid, if local swelling is severe (e.g. prednisolone 40 mg/day for 3–5 days).
• If the airway is affected, treat urgently as anaphylaxis.
• Treat urgently as for anaphylaxis and admit to hospital anyone with:
• A systemic reaction with respiratory difficulty and/or hypotension.
• A severe generalized reaction (e.g. vomiting, abdominal or uterine cramps, or wheezing).
• For detailed information on the treatment of anaphylaxis, see the CKS topic on Angio-oedema and anaphylaxis.
• If generalized urticaria develops:
• Give an oral antihistamine and a corticosteroid (e.g. prednisolone 40 mg/day for 3–5 days).
• If symptoms progress the person should be advised to seek urgent medical help.
• Admit if mild symptoms progress to a severe reaction (uncommon).
• Consider referral to an allergy clinic if:
• Any previous sting or bite has caused generalized symptoms other than at the site of the sting.
• 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.

• 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 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:
• 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.

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

• 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 will 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 then eliminated.

• 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. See Managing a tick bite for more information.

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

• 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 [BNF 52, 2006].

• 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].
• 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].

• 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 oral steroids (e.g. prednisolone for 3–5 days if local swelling is severe).
• If the airway is affected, treat urgently as anaphylaxis — see the CKS topic on Angio-oedema and anaphylaxis for more information.

• 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 daily for 3–5 days.

• 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].

• 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.
• 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.
• 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 difficulties occur.

• Some drugs, such as beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, alpha-blockers, monoamine oxidase inhibitors, or tricyclic antidepressants, may increase the severity of the reaction.
• Anyone with a history of chronic lymphoid leukaemia may exhibit severe or delayed bite reactions.

• 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].

• 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.

• 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].

• Treat empirically with oral antibiotics for 7 days:
• Oral flucloxacillin is recommended for empirical treatment of staphylococcal and streptococcal skin infections.
• Oral erythromycin (or clarithromycin if erythromycin is not tolerated) is an alternative for people with penicillin-allergy.

• 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 (methicillin-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].

• Admit all patients with anaphylaxis, after immediate emergency management.
• If mild symptoms appear to be worsening, 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.

• 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.

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

• 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

• 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].

This follow-up advice only applies to people who are not admitted to hospital (i.e. are being managed in primary care).

• If a person has a local reaction to an insect bite or sting:
• Follow-up is not usually required unless symptoms are worsening.
• If the person presents with a severe local reaction, consider reviewing within 2–3 days.
• If a person presents with generalized urticaria:
• If symptoms are mild, follow-up is not usually necessary.
• Advise review if they have worsening urticaria.
• Advise urgent medical review if symptoms of systemic toxicity develop.
• Remember to consider indications for referral to an allergy clinic.

• These recommendations are based on pragmatic advice.

• 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.

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

• 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.

• 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.

• 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]

• 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.

• These recommendations are based on expert opinion from the medical literature [Parish and Schwartzman, 1993; Hunter et al, 2002; Burns, 2004; Royal Pharmaceutical Society, 2005].

• 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.

• Seek veterinary advice for the most appropriate treatment to eliminate an infestation.

• These recommendations are based on expert opinion from the medical literature [Parish and Schwartzman, 1993; Hunter et al, 2002; Burns, 2004].