Often diagnosis is a clinical one.
General measures include:
- crotamiton/hydrocortisone preparations e.g. Eurax/hydrocortisone (R) - crotamiton is an anti - parasitic drug; hydrocortisone has a useful anti - inflammatory effect. An alternative topical agent is a combination of fusidic acid/hydrocortisone cream
- calamine lotion
- antihistamines - useful if itch is a prominent symptom
- antibiotics - if bacterial sepsis present
NICE suggest (1):
Clinicians need to be aware that:
- a rapid-onset skin reaction from an insect bite or sting is likely to be an inflammatory or allergic reaction, rather than an infection
- most insect bites or stings will not need antibiotics
Assess the type and severity of the insect bite or stings to identify:
- a local inflammatory or allergic skin reaction
- erythema migrans (bullseye rash), a sign of Lyme disease (see linked item)
- symptoms or signs of an infection
- a systemic reaction (see the recommendations on referral and seeking specialist advice below)
Advise people with an insect bite or sting that:
- a community pharmacist can advise about self-care treatments
- skin redness and itching are common and may last for up to 10 days
- it is unlikely that the skin will become infected
- avoiding scratching may reduce inflammation and the risk of infection
- they should seek medical help if symptoms worsen rapidly or significantly at any time, or they become systemically unwell
For people with a known or suspected tick bite, follow the NICE guideline on Lyme disease.
Treatment for local inflammatory or allergic skin reaction
- do not offer an antibiotic for an insect bite or sting in people who do not have symptoms or signs of an infection
- be aware that people may wish to consider oral antihistamines (in people aged over 1 year) to help relieve itching, even though there is uncertainty about their effectiveness in managing insect bites or stings. Some antihistamines cause sedation, which may help at night
Treating an infected insect bite or sting
- for people with an insect bite or sting who have symptoms or signs of an infection, see the recommendations on choice of antibiotic in the NICE guideline on cellulitis and erysipelas
Reassessment
- reassess people with an insect bite or sting if:
- symptoms or signs of an infection develop (see the NICE guideline on cellulitis and erysipelas)
- their condition worsens rapidly or significantly, or they become systemically unwell
- they have severe pain out of proportion to the wound, which may indicate the presence of toxin-producing bacteria
Referral and seeking specialist advice
- refer people with an insect bite or sting to hospital if they have symptoms or signs suggesting a more serious illness or condition, such as a systemic allergic reaction
- consider referral or seeking specialist advice for people with an insect bite or sting if:
- they are systemically unwell
- they are severely immunocompromised, and have symptoms or signs of an infection
- they have had a previous systemic allergic reaction to the same type of bite or sting
- it is in the mouth or throat, or around the eyes
- it has been caused by an unusual or exotic insect
- they have fever or persisting lesions associated with a bite or sting that occurred while travelling outside the UK
Key points (2):
- most insect bites or stings will not need antibiotics
- do not offer an antibiotic if there are no symptoms or signs of infection
- If there are symptoms or signs of infection, see NICE guideline on cellulitis and erysipelas
Reference: