Lyme disease

Question 1

Cause

Answer 1

Borrelia burgdorferi (spirochete)

Spread by ticks

Question 2

Early features (within 30 days)

Answer 2

Erythema migrans
- ‘bulls-eye’ rash at site of tick bite
- typically develop 1-4 weeks after initial bite
- usually painless

Systemic features
- headache
- lethargy
- fever
- arthralgia

Question 3

Later features (after 30 days)

Answer 3

CVD
- heartblock
- peri-myocarditis

Neurological
- facial nerve palsy
- radicular pain
- meningitis

Question 4

Investigations

Answer 4

Clinical diagnosis if erythema migrans present

ELISA antibodies to Borrelia burgdorferi

Question 5

Management of asymptomatic tick bite

Answer 5

Tick still present: remove with fine-tipped tweezers

No routine antibiotics

Question 6

Management of suspected/ confirmed Lyme disease

Answer 6

Doxycycline if early disease (amoxicillin if doxy contraindicated)

Ceftriaxone if disseminated disease

Jarisch-Herxheimer reaction sometimes seen after initiating therapy

Question 7

Jarisch-Herxheimer reaction

Answer 7

Fever, rash and tachycardia after first dose of antibiotic

More commonly seen in syphillis