Take single-dose doxycycline prophylaxis after a tick bite

A single 200 mg dose of doxycycline taken within 72 hours of removing an Ixodes scapularis tick can prevent Lyme disease with 87% efficacy. This is recommended for high-risk bites where the tick was attached for 36 hours or more in an endemic area. Children receive 4.4 mg/kg (max 200 mg) as a single dose.

Why It Works

Borrelia burgdorferi transmission typically requires 36-48 hours of tick attachment. A single high dose of doxycycline administered shortly after removal can eliminate spirochetes before they disseminate. The 2020 IDSA/AAN/ACR guidelines strongly recommend this approach for qualifying bites.

Tips

• Only recommended when all high-risk criteria are met (Ixodes tick, endemic area, 36+ hours attached)
• Without all high-risk features, monitoring for symptoms is equally effective
• Nausea is the most common side effect (15% of recipients)
• Mark the calendar for 30 days post-bite and watch for erythema migrans rash