Lyme disease

Question 1

What causes Lyme disease?

Answer 1

caused by the spirochaete Borrelia burgdorferi and is spread by ticks.

Question 2

Early features of Lyme disease? (within 30 days)

Answer 2

erythema migrans
- ‘bulls-eye’ rash is typically at the site of the tick bite
- typically develops 1-4 weeks after the initial bite but may present sooner
- usually painless, more than 5 cm in diameter and slowly increases in size
- present in around 80% of patients.

systemic features
- headache
- lethargy
- fever
- arthralgia

Question 3

Later features (after 30 days) of lyme disease?

Answer 3

Cardiovascular: heart block, peri/myocarditis

Neurological: facial nerve palsy, radicular pain, meningitis

Question 4

Investigation of lyme disease

Answer 4

NICE recommend that Lyme disease can be diagnosed clinically if erythema migrans is present

• erythema migrans is therefore an indication to start antibiotics

enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test

• if negative and Lyme disease is still suspected in people tested within 4 weeks from symptom onset, repeat the ELISA 4-6 weeks after the first ELISA test. If still suspected in people who have had symptoms for 12 weeks or more then an immunoblot test should be done
• if positive or equivocal then an immunoblot test for Lyme disease should be done

Question 5

Management of asymptomatic tick bites

Answer 5

tick bites can be a relatively common presentation to GP practices, and can cause significant anxiety

if the tick is still present, the best way to remove it is using fine-tipped tweezers, grasping the tick as close to the skin as possible and pulling upwards firmly. The area should be washed following.

NICE guidance does not recommend routine antibiotic treatment to patients who’ve suffered a tick bite

Question 6

Management of suspected/confirmed Lyme disease

Answer 6

doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
- people with erythema migrans should be commenced on antibiotic without the need for further tests

• ceftriaxone if disseminated disease
• Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)