What is the recommended prophylaxis for pediatric Lyme disease?

Pediatric Lyme Disease Prophylaxis

For pediatric Lyme disease prophylaxis, a single dose of doxycycline (4 mg/kg, up to a maximum dose of 200 mg) is recommended for children ≥8 years of age when specific high-risk criteria are met. 1

Prophylaxis Criteria

Prophylactic treatment with doxycycline should be offered when ALL of the following conditions exist:

1. The tick can be reliably identified as an adult or nymphal Ixodes scapularis tick
2. The tick is estimated to have been attached for ≥36 hours (based on engorgement or known time of exposure)
3. Prophylaxis can be started within 72 hours of tick removal
4. The local rate of Borrelia burgdorferi infection in ticks is ≥20% (typically in parts of New England, mid-Atlantic states, Minnesota, and Wisconsin)
5. Doxycycline is not contraindicated 1

Age-Specific Recommendations

• Children ≥8 years: Single dose of doxycycline (4 mg/kg, maximum 200 mg) 1, 2
• Children <8 years: Prophylactic antibiotics are generally not recommended due to traditional concerns about dental staining with doxycycline 1

Important Considerations

• The Infectious Diseases Society of America (IDSA) guidelines specifically recommend against substituting amoxicillin for doxycycline in children <8 years due to:

  • Lack of data on effective short-course prophylaxis regimens
  • Need for multi-day regimens with associated adverse effects
  • Excellent efficacy of treatment if infection develops
  • Extremely low risk of serious complications from a recognized tick bite 1

• Recent evidence suggests increasing use of doxycycline in children <8 years for Lyme disease treatment, with the American Academy of Pediatrics stating in 2018 that courses of doxycycline ≤3 weeks may be safe in children of all ages 3. However, this applies to treatment rather than prophylaxis, and the IDSA guidelines remain the standard for prophylaxis.

When Prophylaxis is Not Recommended

• Routine prophylaxis after all tick bites is not recommended 1
• Prophylaxis is not generally necessary after Ixodes pacificus bites (West Coast) due to low infection rates 1
• When the tick has been attached for <36 hours
• When >72 hours have elapsed since tick removal
• When the local infection rate in ticks is <20%

Alternative Approach When Prophylaxis is Not Given

For children who do not receive prophylaxis after a tick bite:

1. Observe for signs and symptoms of Lyme disease for 30 days
2. Monitor especially for the development of erythema migrans (expanding red rash) at the bite site
3. Seek prompt medical attention if symptoms develop 1

Treatment if Infection Develops

If a child develops Lyme disease:

• Children ≥8 years: Doxycycline (4 mg/kg/day in 2 divided doses, maximum 100 mg per dose) for 10-21 days depending on manifestation 1
• Children <8 years: Amoxicillin (50 mg/kg/day in 3 divided doses, maximum 500 mg per dose) or cefuroxime axetil (30 mg/kg/day in 2 divided doses, maximum 500 mg per dose) for 14-21 days 1

Pitfalls to Avoid

• Do not use prophylaxis for all tick bites regardless of risk factors
• Do not substitute amoxicillin for doxycycline in prophylaxis regimens
• Do not delay treatment if symptoms of Lyme disease develop
• Do not assume a previous Lyme disease vaccine or prior infection provides protection against future infections 1
• Do not rely on prophylaxis to prevent other tick-borne infections like Human Granulocytic Anaplasmosis or babesiosis 1

Recent European data shows a 67% relative risk reduction in Lyme disease with single-dose doxycycline prophylaxis, with a number-needed-to-treat of 51 4, supporting the efficacy of this approach when appropriate criteria are met.