From the Guidelines
The recommended treatment duration for erythema migrans is 10-14 days, with doxycycline or amoxicillin being the preferred antibiotic regimens. According to the most recent guidelines 1, patients with erythema migrans should be treated with either a 10-day course of doxycycline or a 14-day course of amoxicillin or cefuroxime axetil.
Key Considerations
- Doxycycline (100 mg twice daily) is the first-line treatment for most adults, while amoxicillin (500 mg three times daily) is preferred for children under 8, pregnant women, and those who cannot take doxycycline 1.
- Alternative options include cefuroxime axetil (500 mg twice daily) for patients allergic to both doxycycline and amoxicillin.
- Treatment should begin as soon as erythema migrans is clinically diagnosed, without waiting for laboratory confirmation, as early intervention prevents progression to later stages of Lyme disease.
- Patients should complete the full course of antibiotics even if symptoms resolve quickly, and they should be monitored for potential side effects such as photosensitivity with doxycycline or gastrointestinal issues with amoxicillin.
Additional Guidance
- The relatively short course is usually sufficient because erythema migrans represents early localized Lyme disease, when the Borrelia burgdorferi bacteria have not yet widely disseminated throughout the body.
- Azithromycin may be used as a second-line agent, with a recommended duration of 5-10 days, and a 7-day course preferred in the United States 1.
From the Research
Treatment Duration for Erythema Migrans
The recommended treatment duration for erythema migrans can vary depending on the antibiotic used and the patient's specific condition.
- Doxycycline is a commonly used antibiotic for treating erythema migrans, with studies suggesting that a 7-day to 14-day course can be effective 2, 3.
- A study published in 2023 found that 7 days of oral doxycycline was non-inferior to 14 days in adults with solitary erythema migrans, with a treatment failure rate of 3% in the 7-day group versus 2% in the 14-day group 2.
- Another study from 2012 compared 10 days and 15 days of oral doxycycline therapy in adult European patients with erythema migrans, finding that the 10-day regimen was not inferior to the 15-day regimen, with a complete response rate of 91.9% in the 10-day group versus 93.4% in the 15-day group 3.
- For children, amoxicillin is commonly used to treat erythema migrans, with a recommended dose of 50 mg/kg/day, administered three times a day, although a study from 2025 suggested that splitting the same daily dose into two administrations (q12h) may provide comparable drug exposure 4.
- Other antibiotics, such as tetracycline, have also been used to treat erythema migrans, with a study from 1995 finding that doxycycline was comparable to tetracycline in terms of safety and efficacy, although there was a trend toward a better outcome with tetracycline at 1 year 5.
- The choice of treatment duration may depend on various factors, including the severity of the disease, the patient's age and health status, and the presence of any underlying medical conditions.
- A study from 1987 suggested that minocycline or high doses of parenteral penicillin may be effective for treating erythema migrans, although the optimal treatment duration was not specified 6.