Intended for healthcare professionals

Practice Practice Pointer

Insect bites

BMJ 2020; 370 doi: (Published 07 August 2020) Cite this as: BMJ 2020;370:m2856
  1. Jane Wilcock, general practitioner, chair of Overdiagnosis Group RCGP, vice chair of NWE Faculty RCGP1,
  2. Clare Etherington, general practitioner, head of Primary Care Education and Training Health Education England (North West London), clinical lead MAP RCGP2,
  3. Kamila Hawthorne, general practitioner, head of Graduate Entry Medicine, Swansea Medical School3,
  4. Graham Brown, primary care librarian4
  1. 1Silverdale Medical Practice, Salford M27 8HP, UK
  2. 2The Ridgeway Surgery, Harrow, UK
  3. 3Cynon Vale Medical Practice, Mountain Ash, UK
  4. 4North Bristol NHS Trust, Bristol, UK
  1. Correspondence to: J Wilcock jane.wilcock{at}

What you need to know

  • There is little research evidence on best practice for insect bites

  • Insect bite reactions vary widely and depend on the insect and the patient’s response

  • Secondary infection may be indicated by fever, systemic symptoms, and worsening reactions with spreading erythema. It can be difficult to know if mild secondary cellulitis has occurred

Insects bites are a common reason for patients to seek medical advice, often with concerns that the skin around the bite might have become infected. Clinicians use a combination of clinical features and risk factors when assessing insect bites, but a lack of evidence for the diagnostic and prognostic value of these features, as well as a lack of data on outcomes, means that most practice is based on clinical experience and custom. This article outlines these uncertainties and offers an approach to assessing a patient in the UK who presents with an insect bite.

What type of insects bite?

In the UK common biting insects include mosquitoes, gnats or midges, ants, fleas, lice, bedbugs, sandflies, and flower bugs (small oval flies). Ticks and spiders (both technically arachnids) can also bite. Clinical assessment varies according to world location and includes consideration of vector-borne illnesses, which are mainly contracted outside the UK. Table 1 lists common vector-borne illness, which are most common in tropical and subtropical countries.1

View this table:
Table 1

Insect and tick vector-borne diseases1

Insect bite uncertainties


The exact incidence of insect bites and stings is not known as most are not reported.23 According to a study of data recorded by sentinel general practices in England and Wales, GP consultations about insect bites are 5.4/100 000 patients per week on average. This rises above 12 per 100 000 in August and September.4 Geography, month, and activity influence insect bite experience. In some parts of the UK insect bites are particularly common. For instance, a questionnaire survey …

View Full Text

Log in

Log in through your institution


* For online subscription