25th February 2025

Lyme disease

Overview of Lyme disease

Lyme disease is caused by the spirochaete Borrelia, with a tick vector (Ixodes) found in grassy and wooded areas. 

Signs and symptoms of Lyme disease

About 25% develop arthralgia, with arthritis less common. This arthritis is often migratory, with brief attacks of swelling in one or more joints; it can become chronic if untreated. Other symptoms are divided into 3 stages, including an early erythema migrans rash and later cardiovascular and neurological complications.

Investigations in Lyme disease

There is an ELISA (enzyme-linked immunosorbent assay) test for antibodies.

Management of Lyme disease

Treatment is with antibiotics for all with erythema migrans or a positive ELISA, with a cure rate of 95%. This is usually doxycycline 100 mg BD for 21 days (or 28 days with arthritis) with a Jarisch-Herxheimer reaction in 15%. This presents with fevers, vasodilation with flushing, tachycardia, headaches and myalgia; hypotension is not a usual feature. Prevention of tick bites is important. In the UK, antibiotic prophylaxis is not routine.