What are the appropriate treatments for toenail disorders, including fungal infections (onychomycosis), ingrown toenails, and nail trauma, in pediatric patients?

Toenail Disorders in Pediatrics: Treatment Approach

Onychomycosis (Fungal Nail Infections)

For dermatophyte onychomycosis in children, terbinafine is the preferred first-line systemic treatment, dosed by weight: 62.5 mg daily for <20 kg, 125 mg daily for 20-40 kg, and 250 mg daily for >40 kg, given for 12 weeks for toenails. 1, 2

Diagnostic Confirmation Required

• Always obtain mycological confirmation before starting treatment - direct microscopy with potassium hydroxide (KOH) preparation and fungal culture are essential, as 50% of dystrophic nails in children are non-fungal despite similar appearance 2, 3
• Examine the child for concomitant tinea pedis and tinea capitis 2, 3
• Screen parents and siblings for onychomycosis and tinea pedis, as household transmission is common 2, 3

Systemic Treatment Algorithm

First-Line Options:

• Terbinafine (generally preferred): Weight-based dosing for 6 weeks (fingernails) or 12 weeks (toenails), with baseline liver function tests and complete blood count required since it is unlicensed for pediatric use 1, 2
• Itraconazole pulse therapy: 5 mg/kg/day for 1 week per month, with 2 pulses for fingernails and 3 pulses for toenails, achieving 94-100% clinical cure rates 1, 3

Second-Line Options (when first-line contraindicated or not tolerated):

• Fluconazole: 3-6 mg/kg once weekly for 18-26 weeks for toenails, with baseline liver function tests and complete blood count 1, 2
• Griseofulvin: 10 mg/kg daily (maximum 500 mg) taken with fatty food, for at least 6 months for toenails 1, 4

Topical Treatment

• Topical monotherapy is more effective in children than adults due to thinner, faster-growing nails 5, 6
• Efinaconazole 10% and tavaborole 5% are FDA-approved for children ≥6 years 6
• Ciclopirox 8% lacquer is approved for children ≥12 years, applied once daily for up to 48 weeks 1, 6
• Amorolfine 5% lacquer applied once or twice weekly for 6-12 months is useful for superficial and distal onychomycosis 1

Critical Management Points

• Children achieve higher cure rates and faster response than adults 2, 3
• Monitor for at least 48 weeks from treatment start to identify potential relapse 2
• Common adverse effects include headache, gastrointestinal upset, and taste disturbance with terbinafine 1
• Terbinafine can aggravate psoriasis and cause subacute lupus-like syndrome 1

Prevention Strategies

• Decontaminate or replace contaminated footwear 2
• Apply antifungal powders inside shoes regularly 2, 3
• Keep nails short and clean 2
• Avoid sharing nail clippers with infected family members 2

Ingrown Toenails (Onychocryptosis)

For mild to moderate ingrown toenails, begin with conservative measures including gutter splinting, correcting footwear, and managing hyperhidrosis; surgical partial nail avulsion with matrixectomy is superior for preventing recurrence in moderate to severe cases. 7

Conservative Treatment (Mild to Moderate Cases)

• Gutter splint application to the ingrown nail edge provides immediate pain relief by separating it from the lateral fold 7
• Place wisps of cotton or dental floss under the ingrown lateral nail edge 7
• Correct inappropriate footwear and manage hyperhidrosis 7
• Soak the affected toe followed by applying mid- to high-potency topical steroid 7
• Cotton nail cast made from cotton and cyanoacrylate adhesive or taping the lateral nail fold 7

Surgical Treatment (Moderate to Severe Cases)

• Partial avulsion of the lateral edge of the nail plate is the most common surgical approach 7
• Matrixectomy (surgical, chemical, or electrosurgical) further prevents recurrence and is superior to nonsurgical approaches 7
• For patients with excessive periungual tissues and curved nails who fail conservative and standard surgical treatments, paronychium flap procedures can provide permanent resolution 8

Key Considerations

• Ingrown toenails are most common among school-age children and adolescents 8
• Causes include increased nail curvature, trauma, and external pressure from footwear 8
• Surgical approaches are superior to nonsurgical ones for preventing recurrence 7

Nail Trauma

Management Approach

• Trauma is a significant predisposing factor for onychomycosis in children, particularly in athletes 1
• Sports involving sudden starting/stopping (tennis, football, cricket) and those without protective footwear (gymnastics, ballet) increase risk 1
• Traumatized nails should be monitored for secondary fungal infection, especially in the presence of tinea pedis 1

Common Pitfalls to Avoid

• Never assume fungal infection without laboratory confirmation - 50% of dystrophic nails are non-fungal 2, 3
• Do not overlook examination of family members, as household transmission is common 2, 3
• Avoid treating based on appearance alone, as multiple conditions can mimic onychomycosis including psoriasis, lichen planus, and bacterial infections 3
• For bacterial infections like Green Nail Syndrome (Pseudomonas), keep the area dry and apply topical povidone iodine 2% twice daily rather than antifungals 3