What is the recommended treatment for Lyme disease in children under 9 years old?

Treatment of Lyme Disease in Children Under 9 Years Old

For children under 9 years old with Lyme disease, amoxicillin at 50 mg/kg/day in 3 divided doses (maximum 500 mg per dose) for 14 days (range 10-21 days) is the recommended first-line treatment. 1

First-Line Treatment Options

For early Lyme disease (characterized by erythema migrans):

• Amoxicillin: 50 mg/kg/day in 3 divided doses (maximum 500 mg per dose) for 14 days (range 10-21 days) 1
• Cefuroxime axetil: 30 mg/kg/day in 2 divided doses (maximum 500 mg per dose) for 14 days (range 10-21 days) 1

Age-Specific Considerations

• Children under 8 years: Doxycycline is traditionally avoided due to concerns about dental staining 2
• Children 8 years and older: Doxycycline can be used at 4 mg/kg/day in 2 divided doses (maximum 100 mg per dose) 1

Treatment Based on Disease Manifestation

Early Localized Disease (Erythema Migrans)

• Oral antibiotics for 14 days (range 10-21 days) 1
• Amoxicillin has shown 100% resolution of constitutional symptoms in clinical studies 3

Neurological Manifestations

• Facial nerve palsy without CSF abnormalities: Oral regimen as for erythema migrans for 14 days 1
• Meningitis or radiculopathy: IV ceftriaxone or cefotaxime (parenteral therapy) 1
• Facial nerve palsy with CSF abnormalities: Treatment as for meningitis 1

Dosing Optimization

Recent pharmacokinetic modeling suggests that amoxicillin at 25 mg/kg/dose given twice daily (q12h) may provide comparable drug exposure to the traditional three-times-daily regimen for MICs between 0.06 and 1 mg/L, which could improve adherence 4. However, the current IDSA guideline still recommends the three-times-daily dosing schedule 1.

Important Clinical Considerations

• Macrolide antibiotics are not recommended as first-line therapy due to lower efficacy 1
• First-generation cephalosporins should be avoided 1
• Treatment duration should not exceed recommended guidelines without clear evidence of treatment failure 1, 5
• Studies show that a 14-day course of amoxicillin is highly effective for early Lyme disease 6

Emerging Evidence on Doxycycline in Young Children

While traditionally avoided in children under 8 years, recent research suggests doxycycline may be generally well-tolerated and effective in young children with Lyme disease 2. However, amoxicillin remains the preferred treatment for non-neurological manifestations in this age group until more definitive evidence is available 2.

Common Pitfalls to Avoid

• Extending antibiotic treatment beyond recommended durations 1
• Using first-generation cephalosporins, which are ineffective 1
• Attributing persistent symptoms to active infection requiring additional antibiotics 1, 5
• Confusing Post-Lyme Disease Syndrome with need for additional antibiotic therapy 1

Treatment Monitoring

• Follow-up evaluations should assess resolution of erythema migrans and constitutional symptoms
• Complete resolution of erythema migrans occurs in approximately 67-92% of patients after treatment completion 3
• Most patients have good outcomes with no long-term problems associated with Lyme disease when treated appropriately 3