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Summary for primary care

Insect Bites and Stings: Antimicrobial Prescribing

This guideline sets out an antimicrobial prescribing strategy for insect and spider bites and stings in adults, young people and children aged 72 hours and over, including those that occurred while travelling outside the UK.

It aims to limit antibiotic use and reduce antibiotic resistance. The recommendations in this guideline were developed before the COVID-19 pandemic.

Read the related Guidelines in Practice article: Bites and stings: when to prescribe an antibiotic

Antimicrobial Prescribing

Algorithm 1: Insect Bites and Stings—Antimicrobial Prescribing

Managing Insect Bites and Stings

Assessment and Advice

  • 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 NICE guideline on Lyme disease)
    • symptoms or signs of an infection
    • a systemic reaction (see the recommendations on referral and seeking specialist advice).
  • 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. 

Treating a 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


  • 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
  • When reassessing people with an insect bite or sting, take account of other possible diagnoses such as Lyme disease (see the NICE guideline on Lyme disease).

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 (see the NICE guideline on anaphylaxis).
  • 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.