Lyme disease

Definition

Infection with the spirochaete Borrelia burgdorferi, transmitted by ticks.

Epidemiology

Pathophysiology

1. First you get a lump at the site of the site, a rash that is centrally sparing called erythema migrans.
2. In the second stage, you get a fever, with malaise and headache. About 60% get a monoarticular arthritis (a single joint arthritis), affecting large joints.
3. If you don't treat it, you go on to get recurrent arthritis, with peripheral neuropathy and encephalopathy.

Risk Factors

Going camping, walking through long grass, or generally being in the countryside in Europe, Northern America or Russia.

Investigations

Serology, with a positive immunoblot.

Management

1. Early disease can be treated with doxycycline, amoxicillin or ceftriaxone.
2. Cephalosporins are needed for second stage arthritis or neurological involvement.
3. Untreated late stage disease does not respond to antibiotics.