What is the treatment for a pediatric infected toenail?

Treatment of Pediatric Infected Toenail (Onychomycosis)

For pediatric onychomycosis of the toenail, first-line treatment is oral terbinafine dosed by weight (62.5 mg daily if <20 kg, 125 mg daily for 20-40 kg, 250 mg daily if >40 kg) for 12 weeks, or alternatively pulse itraconazole 5 mg/kg/day for 1 week per month for 3 months. 1

Diagnostic Confirmation Required

Before initiating any antifungal therapy, mycological confirmation is essential through either direct microscopic examination with potassium hydroxide or fungal culture. 2, 3 This is particularly important in children where onychomycosis is less common (<0.5% prevalence worldwide) and can be easily confused with other nail dystrophies. 1

First-Line Systemic Treatment Options

Terbinafine (Preferred)

• Dosing by weight: 62.5 mg daily if weight <20 kg, 125 mg daily for 20-40 kg, 250 mg daily if >40 kg 1
• Duration: 12 weeks for toenails, 6 weeks for fingernails 1
• Efficacy: Clinical cure rates of 88-100% in pediatric studies, superior to adult populations 1
• Monitoring: Baseline liver function tests and complete blood count recommended, though unlicensed for children in some jurisdictions 1
• Contraindications: Hepatic impairment 1

Itraconazole (Alternative First-Line)

• Dosing: Pulse therapy at 5 mg/kg/day for 1 week per month 1
• Duration: 3 pulses (3 months) for toenails, 2 pulses (2 months) for fingernails 1
• Efficacy: Clinical cure rate of 94-100% in pediatric studies 1
• Administration: Must be taken with food and acidic pH for optimal absorption 1
• Monitoring: Hepatic function tests recommended in patients with pre-existing abnormalities or receiving continuous therapy >1 month 1
• Contraindications: Heart failure, hepatotoxicity 1

Second-Line Options

Fluconazole

• Dosing: 3-6 mg/kg once weekly 1
• Duration: 18-26 weeks for toenails, 12-16 weeks for fingernails 1
• Use when: Itraconazole and terbinafine are contraindicated or not tolerated 1
• Particularly effective for: Candida species infections 1

Griseofulvin (No Longer Recommended as First-Line)

• Dosing: 10 mg/kg/day for children aged 1 month and above 1, 3
• Duration: At least 6 months for toenails 3
• Major limitations: Low efficacy (30-40% mycological cure), long treatment duration, high relapse rates 1
• Only use when: Other agents are unavailable or contraindicated 1

Topical Therapy Considerations

Topical agents may be considered as monotherapy in children due to their thinner, faster-growing nails compared to adults, though no clinical trials demonstrate efficacy specifically in pediatric populations. 1, 4

Available Topical Options:

• Efinaconazole 10% solution: FDA-approved for children ≥6 years, applied daily for 48 weeks, achieving 65% mycological cure and 40% complete cure 5
• Amorolfine 5% lacquer: Applied once or twice weekly for 6-12 months 1
• Ciclopirox 8% lacquer: Applied daily for up to 48 weeks, FDA-approved for children >12 years 1, 5

Topical therapy alone is only appropriate for: very distal infection, superficial white onychomycosis, or when systemic therapy is contraindicated. 1, 2

Why Children Respond Better Than Adults

Children demonstrate higher cure rates (88-100%) and faster response to treatment compared to adults due to: 1

• Thinner nail plates
• Faster nail growth rates
• Better drug penetration

Critical Management Steps

Family Screening

Examine all family members for onychomycosis and tinea pedis, as familial clustering is common and untreated family members serve as reinfection sources. 1, 6

Concomitant Infections

Check for tinea pedis and tinea capitis in the affected child, as these frequently coexist with onychomycosis. 1

Causative Organisms

The dominant pathogens in pediatric onychomycosis are Trichophyton rubrum, T. mentagrophytes, and Candida species. 1 Use azoles (itraconazole or fluconazole) when Candida species are identified. 1, 2

Common Pitfalls to Avoid

1. Starting treatment without mycological confirmation leads to unnecessary systemic antifungal exposure for non-fungal nail dystrophies 2

2. Inadequate treatment duration results in higher relapse rates—complete the full course even if clinical improvement occurs earlier 2, 3

3. Failing to treat concomitant tinea pedis and infected family members leads to reinfection 1, 2

4. Using griseofulvin as first-line therapy when superior alternatives (terbinafine, itraconazole) are available 1

5. Overlooking drug interactions with itraconazole, particularly in children on multiple medications 1

Prevention of Recurrence

• Apply antifungal powder inside shoes regularly 2
• Spray terbinafine solution into shoes periodically 2
• Treat all infected family members simultaneously 1