Lyme disease

Background

• Spirochete Borrelia burgdorferi infection via tick bite

Clinical

• Erythem migrans - macular erythematous rash with central clearing
• Starts at bite site (3-21 days later) and spreads (spirochetes migrate from wound site)
• Rash disappears after 1 month or may never be noticed
• May have accociated "'flu" like fatigue, fever etc

Late symptoms seen in 2/3 if untreated:

• Neuroborreliosis: mononeuritis multiplex (e.g. Bell's) or meningitis
• Oligoarthralgia: (knees) - synovial ↑WCC and PCR +pos for spirochetes
• Pancarditis: AV block, or myocarditis

Investigations

• Serology testing (ask labs) to confirm suspicious cases
• IgG has lower false positive rate than IgM. IgM usually indicates more recent infection butmay saty positive even after treatment
• ECG : typically AV block

Management

• If well with erythema migrans or strong suspicion for Lyme disease - treat with doxycycline then ask for serology testing
• If significant ECG (beware block) or clinical signs of cardiac involvement, admit for ECG monitoring (±pacing) and iv CefTRIaxone. Later switch to po doxycycline
• If neuroborrelleisos - admit neurology
• If oligoarthritis get (sterile procedure) synovial aspirate
• Please contact microbiology for antibiotic advice

Links