What is the recommended treatment for pediatric patients suspected of having Lyme disease?

Treatment of Lyme Disease in Pediatric Patients

For children under 8 years old with Lyme disease, treat with oral amoxicillin 50 mg/kg/day divided into three doses for 14 days; for children 8 years and older, use doxycycline 4 mg/kg/day (maximum 100 mg per dose) divided into two doses for 10-14 days. 1, 2

First-Line Oral Antibiotic Regimens by Age

Children Under 8 Years Old

• Amoxicillin is the preferred agent at 50 mg/kg/day divided into 3 doses (maximum 500 mg per dose) for 14 days 1, 2
• Cefuroxime axetil is an acceptable alternative at 30 mg/kg/day divided into 2 doses (maximum 500 mg per dose) for 14 days 1, 2
• Doxycycline was traditionally avoided in this age group due to tooth staining concerns, but recent evidence shows it is generally well-tolerated with minimal dental effects 3
• Emerging practice patterns show increasing doxycycline use in children under 8 (from 6.9% in 2015 to 67.9% in 2023), though amoxicillin remains guideline-preferred 4

Children 8 Years and Older

• Doxycycline is the preferred first-line agent at 4 mg/kg/day divided into 2 doses (maximum 100 mg per dose) for 10-14 days 1, 2
• Doxycycline has the critical advantage of covering concurrent human granulocytic anaplasmosis (HGA), which can occur simultaneously with Lyme disease 1
• Doxycycline requires only 10 days of therapy compared to 14 days for β-lactam antibiotics due to its longer half-life 1
• Amoxicillin and cefuroxime axetil remain acceptable alternatives if doxycycline is contraindicated 1, 2

Administration and Safety Considerations

Doxycycline-Specific Instructions

• Must be taken with 8 ounces of fluid to reduce esophageal irritation 1, 2
• Should be taken with food to minimize gastrointestinal intolerance 1
• Patients must avoid sun exposure due to significant photosensitivity risk 1

Treatment Duration Nuances

• For doxycycline: 10 days is sufficient 1
• For β-lactam antibiotics (amoxicillin, cefuroxime): full 14 days required due to shorter half-life 1
• A recent pharmacokinetic study suggests amoxicillin 25 mg/kg twice daily may provide comparable exposure to the three-times-daily regimen for typical MICs, potentially improving adherence 5

Neurologic Lyme Disease (Meningitis, Radiculopathy, Cranial Neuropathy)

When neurologic involvement is present, switch to parenteral therapy with ceftriaxone 50-75 mg/kg IV once daily (maximum 2 g) for 14 days (range 10-28 days). 1, 6

• Cranial nerve palsy (especially facial nerve palsy) can be treated with oral antibiotics in the absence of meningitis 7
• For isolated facial nerve palsy without CSF pleocytosis, oral regimens are adequate 7
• A retrospective study of 321 pediatric LNB patients found no difference in clinical outcome between ceftriaxone and doxycycline in children ≥8 years, though prospective trials are needed 8

Second-Line and Alternative Agents

When First-Line Agents Cannot Be Used

• Azithromycin is the preferred second-line agent when patients cannot tolerate both doxycycline and β-lactam antibiotics 7
• Macrolides (azithromycin, clarithromycin, erythromycin) are less effective than first-line agents and should only be used when absolutely necessary 1, 2
• Patients treated with macrolides require close observation to ensure resolution of clinical manifestations 1

Critical Pitfalls to Avoid

Ineffective Antibiotics That Should NEVER Be Used

• First-generation cephalosporins (e.g., cephalexin) are completely inactive against Borrelia burgdorferi and clinically ineffective 1, 2, 6
• Fluoroquinolones, carbapenems, vancomycin, metronidazole, tinidazole, and trimethoprim-sulfamethoxazole are not recommended 7, 6
• Benzathine penicillin G is ineffective for Lyme disease 7, 6

Inappropriate Treatment Practices

• Do not prescribe multiple repeated courses of antimicrobials for the same episode 7
• Do not use combination antimicrobial therapy 7, 6
• Do not use pulsed-dosing regimens (antibiotics on some days but not others) 7
• Do not extend treatment duration far beyond 14-21 days without specific indication 7, 2

Expected Clinical Outcomes and Follow-Up

Recovery Patterns

• Most pediatric patients (78%) experience complete symptom resolution within 6 months of treatment 9
• Approximately 22% report at least one persistent symptom beyond 6 months, but only 9% have functional impairment meeting post-treatment Lyme disease (PTLD) syndrome criteria 9
• Patients who are more systemically ill at diagnosis may take longer to achieve complete response 1
• Less than 10% of individuals do not respond to appropriate antibiotic therapy as evidenced by persistent objective clinical manifestations 1

Monitoring Requirements

• Patients treated with alternative agents (macrolides, cefuroxime) require closer observation to ensure resolution 1
• For Lyme arthritis, if persistent synovitis continues for at least 2 months after completing IV ceftriaxone (or two 4-week oral courses), this defines antibiotic-refractory arthritis requiring rheumatology consultation 7

Special Clinical Scenarios

Lyme Carditis

• Perform ECG only in patients with symptoms consistent with carditis (dyspnea, edema, palpitations, lightheadedness, chest pain, syncope) 7
• Hospital admission with continuous ECG monitoring is required for PR interval >300 milliseconds, other arrhythmias, or clinical myopericarditis 7
• Treatment duration is 14-21 days with either oral or parenteral antibiotics depending on severity 6

Distinguishing from Other Conditions

• In endemic areas where both Lyme disease and Southern Tick-Associated Rash Illness (STARI) occur, if the rash cannot be distinguished from erythema migrans, treat as Lyme disease 7
• Lyme meningitis in children typically presents with longer duration of illness (median 17 days), less fever, and presence of erythema migrans, cranial nerve palsy, or papilledema in ~90% of cases 7