Makindo Medical Notes

Related Subjects: |Fever in a traveller |Bell's (Facial nerve) Palsy

🦠 Lyme disease is a multisystem inflammatory disorder caused by the spirochaete Borrelia burgdorferi. 🐞 Transmitted by Ixodid (deer) ticks, it is common in the USA, Asia, and Europe. 💡 Early recognition and treatment are crucial to prevent long-term complications.

🔬 Infectious Agents

• Borrelia burgdorferi sensu stricto – USA.
• Borrelia afzelii – Europe (skin manifestations such as acrodermatitis).
• Borrelia garinii – Europe (neuroborreliosis).
• All transmitted by Ixodes ticks (I. scapularis, I. ricinus).

📅 Seasonality

• Spring and summer: higher tick activity.
• Linked to woodland, grassy and rural environments.

📖 Clinical Stages

🧠 Bannwarth’s Syndrome

• Painful radiculitis + lymphocytic meningitis.
• Often with multiple cranial nerve palsies, radiculopathy, and peripheral motor deficits.

🧪 Investigations

• Serology: ELISA → confirmed with Western blot. May be negative early but nearly always positive late.
• IgM = early infection; rising titres suggest recent disease (beware false positives).
• PCR: CSF, joint aspirate, skin biopsy useful in neuroborreliosis.
• CSF: lymphocytic pleocytosis, ↑ protein.
• MRI: white matter changes may mimic demyelination.

🛡️ Prevention

• Prompt tick removal (<24h) reduces transmission risk.
• Protective clothing + tick repellents in endemic zones.
• Check skin folds, scalp, behind knees after outdoor exposure.
• No widely available human vaccine (some under development).
• PEP: Doxycycline 200 mg single dose can reduce risk if given within 72h of high-risk bite.

💊 Management

• Early/localized disease: Doxycycline 100 mg BD × 14 days (Amoxicillin if pregnant or child).
• Alternative agents: Amoxicillin, Cefuroxime, Azithromycin.
• Late/disseminated disease: Longer courses (14–30 days). Severe neuro/cardiac disease → IV Ceftriaxone or Benzylpenicillin.
• Jarisch–Herxheimer reaction: Temporary worsening after starting antibiotics due to spirochaete die-off.
• Carditis: Usually resolves with antibiotics; pacing rarely required.
• Bell’s palsy (Lyme-associated): Doxycycline 100 mg BD × 2–4 weeks (if no contraindication).

📌 Key Points & Considerations

• Long-term sequelae possible if untreated: arthritis, neuropathy, cognitive impairment.
• Complicated disease → discuss with infectious disease specialists.
• Public health: tick control, awareness campaigns, and early treatment reduce morbidity.

📚 References

• CDC – Lyme Disease
• UpToDate: Lyme Disease (clinical guidance).
• NICE: Lyme Disease Management Guidelines.

💡 Exam Pearl: The triad of erythema migrans, facial palsy, and AV block is highly suggestive of Lyme disease.