Early disease manifestations

Around 50-70% of patients are aware of the bite which begins as a red macule or papule at the site of tick bite, most commonly in the groin, the thigh and the axilla.

• occurs at a median of 21 days (range 3–32 days) following a tick bite
• subsequently this lesion expands into ‘target-like’ rash of erythema migrans (EM)
  • is the commonest clinical manifestation of Lyme disease and is seen in around 60%–90% of cases
  • although EM is classically described as having a bull’s eye appearance, around two thirds of single erythema migrans lesions either are uniformly erythematous or have enhanced central erythema without clearing around it
  • common sites include: the groin, axilla, waist, back, legs, and, in children, the head and neck (may occur anywhere on the body surface)
  • may be asymptomatic, mildly pruritic, or, in rare cases, painful
  • if untreated, lesions may become 61 cm (2 ft) in diameter or larger and may last for 3 to 4 weeks before resolving (1,2)

Assocaited non-specific constitutional symptoms are more likely to be seen in infections acquired in North America (3):

• fever and headache
• chills
• stiff neck
• arthralgia and myalgia
• lymphadenopathy
• lethargy and fatigue
• hepatomegaly

Atypical symptoms may be present infrequently

• respiratory symptoms - cough or rhinorrhea
• gastrointestinal symptoms - vomiting or diarrhoea (2)

With or without treatment these initial clinical manifestations resolve within 3 to 4 weeks although the dermatologic manifestations may recur (2).

Reference:

• (1) Dubrey SW et al. Lyme disease in the United Kingdom. Postgrad Med J. 2014;90(1059):33-42
• (2) Shapiro ED. Lyme Disease. The New England journal of medicine. 2014;370(18):1724-1731.
• (3) National Travel Health Network and Centre (NaTHNaC) 2007. Travel Health Information Sheets: Lyme disease.
• (4) Wormser GP. Clinical practice. Early Lyme disease. N Engl J Med. 2006;354(26):2794-80.