Intended for healthcare professionals

Practice 10-Minute Consultation

Tick bite and early Lyme borreliosis

BMJ 2012; 344 doi: (Published 14 May 2012) Cite this as: BMJ 2012;344:e3124
  1. Christopher J A Duncan, research fellow12,
  2. George Carle, general practitioner3,
  3. R Andrew Seaton, consultant in infectious diseases and general (internal) medicine1
  1. 1Brownlee Centre for Infection, Tropical Medicine and Counselling, Gartnaval Hospital, Glasgow G12 0YN, UK
  2. 2Sir William Dunn School of Pathology, Oxford OX1 3RE, UK
  3. 3Kyles Medical Centre, Tighnabruaich, Argyll PA21 2BE, UK
  1. Correspondence to: C J A Duncan chrisduncan{at}
  • Accepted 6 February 2012

A 48 year old man removed two ticks attached to his leg while walking in the Scottish Highlands. A week later he develops a rash and consults you worried about Lyme disease.

What you should cover

Epidemiology—Lyme borreliosis is the commonest tick-borne infection in the northern hemisphere. It is relatively uncommon in the UK overall (about 1200 cases in 2009), but marked geographical variation is observed. Risk is highest in rural forested areas and heathland such as the Highlands (incidence 56.35/100 000 in 2009-101), Lake District, and New Forest. Some 15–20% of infections are acquired in Europe or the US. There has been a steady rise in cases diagnosed in the UK over the past decade.2 3

Risk assessment—Ask about duration of hard bodied (Ixodes) tick attachment, with or without engorgement (fig 1). Transmission of pathogenic Borrelia species is unlikely if ticks are attached for <24 hours and unengorged.2 4


Fig 1 Fully engorged female Ixodes ricinus (courtesy of Dr Alan S Bowman, University of Aberdeen)

Clinical features—Erythema migrans (fig 2) occurs in 90% of symptomatic Lyme borreliosis 2–40 days after exposure.2 3 4 Classic erythema migrans is annular with central clearing (differential diagnosis includes ringworm and erythema multiforme), but in the early stages it can be homogenous and easily confused with cellulitis or insect bite hypersensitivity, and multiple lesions can follow haematogenous spread.4 Non-specific febrile illness without rash occurs in 7% of early Lyme borreliosis in the US.3 Neuroborreliosis can occur in early infection and usually presents with meningitis or cranial nerve palsies (such as facial nerve).2 3 4 Cardiac involvement (heart block) is extremely rare.2 3 4


Fig 2 Classic erythema migrans. Note the central clearing

What you should do

  • Examine the rash.

  • Discuss testing. Erythema migrans is a clinical diagnosis and does not require serological confirmation. Serology is indicated only for diagnostic uncertainty or neurological involvement. Such patients (and any with immunocompromise) should be discussed with an infection specialist. Paired blood samples taken at a four week interval may be required since seroconversion can take several weeks.2

  • Asymptomatic individuals with tick bite should not be tested for Lyme borreliosis (false positives occur because of past resolved infection and cross reactive antibodies), nor should they receive prophylactic treatment (see below).2 Clinical features should be explained with advice to return if symptoms develop.2

  • Treat erythema migrans for 14 days (range 14–21 days)4 with oral doxycycline (100 mg twice daily) or amoxicillin (500 mg three times daily). For pregnant or breastfeeding women or children aged <12 years, the British Infection Association lists alternative treatments.2 (See the British National Formulary for paediatric dosing.2)

  • Explore the patient’s concerns. Early Lyme borreliosis has a good clinical outcome.2 3 4 Cure was observed in 95% of those treated for erythema migrans in a prospective study.5 Non-specific symptoms such as fatigue or headache are common in the general population6 and are no more likely in people treated for Lyme borreliosis at 6-12 months.5 7

  • Give advice on prevention:

    • - Cover skin with long sleeved clothing in forested areas. Insect repellents such as DEET applied to skin and permethrin treatment of clothing are also effective.

    • - Check carefully at least daily for ticks, and remove them gently (without twisting) by grasping as close to the skin as possible with tweezers or a commercial tick removal device. Using nail polish, match ends, etc, to remove ticks can increase the risk of transmission by irritating or rupturing the tick, causing injection or release of infected material.2

    • - Prophylactic treatment of tick bites is rarely indicated in the UK. It may be indicated in special circumstances such as immunocompromise2 or after exposure to tick bites in specific regions such as parts of New England, USA, where tick infection prevalence is >20% and exposure occurred <72 hours previously.4 Discuss chemoprophylaxis with an infection specialist.

Useful reading

Patient information


Cite this as: BMJ 2012;344:e3124


  • This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs

  • We thank Dr Alan S Bowman, University of Aberdeen, for providing the image in fig 1.

  • Contributions: CJAD conceived of the article, and wrote the article with GC and RAS. RAS is guarantor.

  • Competing interests: All authors have completed the Unified Competing Interest form at and declare: no support from any organisation for the submitted work and no financial relationships with any organisations that might have an interest in the submitted work in the previous three years. RAS has received fees for expert testimony relating to medicolegal work about Lyme borreliosis, and GC has received fees from Onmedica for development of educational materials relating to Lyme borreliosis.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

  • Patient consent obtained.


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