Treatment for Tick-Borne Relapsing Fever (TBRF)
Doxycycline is the definitive treatment of choice for tick-borne relapsing fever and should be initiated immediately upon clinical suspicion without waiting for laboratory confirmation. 1
First-Line Treatment
Adults:
- Doxycycline 100 mg twice daily (orally or intravenously) 2, 1
- Duration: 5-7 days minimum and at least 3 days after fever resolution and clinical improvement 1
Children:
- Doxycycline 2.2 mg/kg body weight twice daily (orally or intravenously) for children weighing <45 kg 2, 1
- Despite historical concerns, doxycycline is now recommended for children of all ages with TBRF 2
- Limited courses of doxycycline do not pose substantial risk for tooth staining in children 2
Alternative Treatments
For patients with severe doxycycline allergy:
- Penicillin V or Penicillin G preparations are effective alternatives 3
- Erythromycin can be used as an alternative macrolide option 3, 4
For pregnant patients:
- Tetracyclines are generally contraindicated during pregnancy but may be warranted in life-threatening situations 2
- Carefully weigh risks and benefits as TBRF during pregnancy can lead to serious complications including spontaneous abortion, preterm delivery, or perinatal mortality 5
Clinical Response Expectations
- Fever typically subsides within 24-48 hours after initiating appropriate treatment 1
- If no clinical improvement occurs within 48 hours, consider alternative diagnoses 2, 1
Important Monitoring Considerations
Jarisch-Herxheimer Reaction (JHR)
- Patients must be closely monitored for Jarisch-Herxheimer reactions after initiating antibiotic therapy 4
- JHR occurs in approximately 19.3% of TBRF cases 6
- Characterized by acute worsening of symptoms, fever, hypotension, and tachycardia within hours of first antibiotic dose
- Supportive care is essential during JHR episodes
Diagnostic Considerations
- Laboratory confirmation is made by detection of spirochetes in thin or thick blood smears obtained during a febrile episode 4
- Blood samples should be collected during febrile periods when spirochetemia is highest
- Microscopy remains the diagnostic gold standard in most clinical settings 6
Prevention Strategies
- Preventive antibiotic therapy is not recommended for patients with recent tick bites who are not ill 2
- In endemic regions, avoid rodent and tick-infested areas
- Use insect repellents and protective clothing to prevent tick bites 4
Treatment Pitfalls to Avoid
- Do not delay treatment while awaiting laboratory confirmation 1
- Avoid sulfa-containing antimicrobials, which have been associated with increased severity of tick-borne rickettsial diseases 2
- Beta-lactams, macrolides, aminoglycosides, and sulfonamides are generally not effective for other tick-borne rickettsial diseases, but penicillins are specifically effective for TBRF 2, 3
- Do not mistake rash development during treatment as a drug eruption, as it may be a manifestation of the illness itself 2
Early diagnosis and prompt treatment are essential to prevent complications and reduce mortality associated with TBRF.