From the Guidelines
The treatment for a tick bite with erythema migrans is oral antibiotic therapy with doxycycline, amoxicillin, or cefuroxime axetil, as recommended by the Infectious Diseases Society of America (IDSA) in their 2020 guidelines 1.
Key Considerations
- Doxycycline is the preferred first-line treatment for adults, typically prescribed at 100 mg twice daily for 10-14 days.
- For children under 8 years, amoxicillin is preferred at 50 mg/kg/day divided into three doses (maximum 500 mg per dose) for 14-21 days.
- Alternative options include cefuroxime axetil (500 mg twice daily for adults; 30 mg/kg/day divided twice daily for children) or azithromycin if other medications cannot be used.
Rationale
The IDSA guidelines recommend oral antibiotic therapy for the treatment of erythema migrans, with doxycycline, amoxicillin, and cefuroxime axetil being the preferred agents 1. This recommendation is based on moderate-quality evidence and is intended to prevent the progression of Lyme disease to later stages.
Important Notes
- Treatment should begin promptly upon identification of erythema migrans, without waiting for laboratory confirmation.
- Patients should monitor for resolution of symptoms and report any new or worsening symptoms to their healthcare provider.
- The rash typically begins to fade within days of starting antibiotics, though it may temporarily expand before improving.
Additional Guidance
The 2020 IDSA guidelines also note that macrolide antibiotics, such as azithromycin, are not recommended as first-line therapy, but may be used as an alternative in patients who are intolerant of or cannot take doxycycline, amoxicillin, or cefuroxime axetil 1.
From the FDA Drug Label
Early Lyme Disease: Two adequate and well-controlled studies were performed in patients with early Lyme disease. In these studies all patients had to present with physician-documented erythema migrans, with or without systemic manifestations of infection Patients were randomized in a 1:1 ratio to a 20-day course of treatment with cefuroxime axetil 500 mg twice daily or doxycycline 100 mg 3 times daily.
The treatment for a tick bite with erythema migrans is cefuroxime axetil 500 mg twice daily for 20 days or doxycycline 100 mg 3 times daily for 20 days 2.
- Cefuroxime axetil and doxycycline were effective in preventing the development of sequelae of late Lyme disease.
- The choice of antibiotic should be based on the patient's medical history, allergy status, and other factors.
- It is essential to note that these treatments are specifically for early Lyme disease with erythema migrans and may not be suitable for other manifestations of Lyme disease.
From the Research
Treatment for Tick Bite with Erythema Migrans
The treatment for a tick bite with erythema migrans typically involves antibiotics. The following are some of the commonly recommended treatments:
- Amoxicillin: 50 mg/kg/day in 3 intakes for 14-21 days for adults and children 3, 4, 5, 6
- Doxycycline: 100 mg bid for 14-21 days for adults, and 4 mg/kg/day in 2 intakes for children above 8 years of age 3, 5, 7
- Cefuroxime axetil: 500 mg twice daily for adults, and 30 mg/kg/day in 2 intakes for children 3, 4
- Azithromycin: 500 mg/day for adults, and 20 mg/kg/day for children for 7-10 days 3, 6
Considerations for Treatment
When treating erythema migrans, it is essential to consider the following:
- The diagnosis of erythema migrans is based on clinical findings, and serological tests are not useful at this stage of the infection 5
- Antibiotics should be prescribed only if erythema migrans develops, to avoid unnecessary treatment and adverse effects 5
- Doxycycline should not be used to treat pregnant or breast-feeding women, or children under 8 years old, due to a risk of tooth and bone disorders in children 5
- The efficacy and safety of antibiotics for treating Lyme disease are still controversial, and more research is needed to determine the best treatment options 6
Efficacy and Safety of Antibiotics
Studies have shown that:
- Amoxicillin, doxycycline, cefuroxime, and ceftriaxone have similar efficacy in treating erythema migrans, with a clearance rate of around 90% 3, 5, 6
- Azithromycin appears to have lower efficacy compared to other antibiotics 5, 6
- Cefuroxime and penicillin are safe for treating Lyme disease, with a low frequency of adverse effects 4, 6