What is the recommended first‑line oral therapy for tinea capitis in children and adults, including dosing, duration, and alternative agents?

Tinea Capitis Treatment

First-Line Therapy: Organism-Directed Approach

For tinea capitis, the optimal treatment depends on the causative organism: terbinafine is preferred for Trichophyton species infections, while griseofulvin remains the agent of choice for Microsporum species. 1

Trichophyton Species (Most Common in North America)

Terbinafine is the first-line agent with weight-based dosing: 1

• Children <20 kg: 62.5 mg daily for 2-4 weeks 1
• Children 20-40 kg: 125 mg daily for 2-4 weeks 1
• Children >40 kg and adults: 250 mg daily for 2-4 weeks 1

Terbinafine demonstrates superior efficacy for T. tonsurans infections with a 94% cure rate and shorter treatment duration compared to griseofulvin, improving compliance. 2 The medication compartmentalizes in hair and skin, allowing these abbreviated courses. 3

Microsporum Species

Griseofulvin remains the preferred agent for Microsporum infections: 1

• Children <50 kg: 15-20 mg/kg/day for 6-8 weeks 1
• Children >50 kg and adults: 1 g/day for 6-8 weeks 1

The FDA-approved dosing for griseofulvin is 10 mg/kg daily, but many experts recommend higher doses of 20-25 mg/kg/day due to increasing treatment failures with standard dosing. 4, 3 Treatment must continue for 4-6 weeks for tinea capitis according to FDA labeling. 4

Alternative Oral Agents

Itraconazole

• Dosing: 5 mg/kg/day for 2-3 weeks 2
• Efficacy: 86% cure rate, effective against both Trichophyton and Microsporum species 1, 2
• Key consideration: Significant drug interactions with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin; contraindicated in heart failure 1

Fluconazole

• Dosing: 6 mg/kg/day for 2-3 weeks 2
• Efficacy: 84% cure rate 2
• Advantage: Available in liquid formulation, making it preferred for younger children who cannot swallow tablets 3

Critical Management Principles

Diagnostic Confirmation

Obtain mycological confirmation before treatment whenever possible through KOH microscopy and fungal culture using scalp scraping, hair pluck, or brush sampling. 1 However, if kerion, severe scaling, lymphadenopathy, or alopecia are present, start treatment immediately without waiting for culture results. 1

Treatment Endpoints

The definitive endpoint must be mycological cure (negative microscopy and culture), not just clinical improvement. 1 Repeat mycology sampling at the end of the standard treatment period and continue monthly until mycological clearance is documented. 1

Baseline Monitoring

Obtain baseline liver function tests before initiating terbinafine or itraconazole, especially in patients with pre-existing hepatic abnormalities or when prolonged therapy is anticipated. 1 For treatment courses ≤4 weeks, ongoing monitoring for liver enzyme elevations is generally unnecessary. 3

Adjunctive Therapy

Topical Antifungal Shampoos

Apply sporicidal shampoos (2% ketoconazole or 1% selenium sulfide) to aid in removing adherent scales and hasten eradication of viable spores, potentially decreasing transmission. 3, 5 These are adjuncts only—topical therapy alone is insufficient for tinea capitis. 6

Management of Kerion

Kerion represents a delayed inflammatory host response, not bacterial infection, and does not require antibiotics. 1 Consider topical or oral corticosteroids for symptomatic relief of severe inflammation, though evidence for this practice is mixed. 1, 3

Dermatophytid Reactions

Pruritic papular eruptions may occur after treatment initiation, representing a cell-mediated response to dying dermatophytes. 1 Do not discontinue antifungal therapy; treat symptomatically with topical corticosteroids. 1

Prevention of Transmission and Recurrence

Screen and treat all family members, as over 50% may be affected with anthropophilic species like T. tonsurans. 7 Clean all contaminated combs, brushes, and towels with disinfectant or 2% sodium hypochlorite solution. 7 Cover lesions during treatment and avoid sharing personal items. 7

Common Pitfalls

Avoid using topical antifungals alone for tinea capitis—systemic therapy is mandatory because the infection involves the hair shaft. 6 Do not discontinue therapy based solely on clinical improvement; mycological cure must be documented. 1 If clinical improvement occurs but mycology remains positive, continue current therapy for an additional 2-4 weeks. 1