What is the best treatment for tinea (ringworm of the scalp) capitis?

Treatment of Tinea Capitis

Organism-Directed First-Line Therapy

The best treatment for tinea capitis depends on the causative organism: terbinafine is superior for Trichophyton species infections (2-4 weeks), while griseofulvin is more effective for Microsporum species infections (6-8 weeks). 1, 2

For Trichophyton Species (T. tonsurans, T. violaceum, T. soudanense)

Terbinafine is the preferred first-line agent due to its fungicidal activity and superior efficacy against Trichophyton species 1, 2:

• Weight-based dosing 1, 2:

  • <20 kg: 62.5 mg daily for 2-4 weeks
  • 20-40 kg: 125 mg daily for 2-4 weeks

  • 40 kg: 250 mg daily for 2-4 weeks

• Advantages: Shorter treatment duration (2-4 weeks vs 6-8 weeks for griseofulvin) improves compliance 1

• Side effects: Gastrointestinal disturbances and rashes in <8% of children, with only 0.8% requiring discontinuation 1

For Microsporum Species (M. canis, M. audouinii)

Griseofulvin is the preferred first-line agent and remains the only licensed treatment for tinea capitis in children in the UK 1, 2:

• Weight-based dosing 1, 2, 3:

  • <50 kg: 15-20 mg/kg/day for 6-8 weeks (single or divided dose)

  • 50 kg: 1 g/day for 6-8 weeks (single or divided dose)

• Critical caveat: Terbinafine fails against Microsporum because it cannot be incorporated into hair shafts in prepubertal children and doesn't reach the scalp surface where arthroconidia are located 1

• Important note: 8 weeks of griseofulvin is significantly more effective than 4 weeks of terbinafine for confirmed Microsporum infection 1

When to Start Treatment Empirically

Begin treatment before mycology results if any cardinal clinical signs are present: scale, lymphadenopathy, alopecia, or kerion 1, 2:

• Collect specimens via scalp scrapings, hair pluck, brush, or swab for microscopy and culture 1, 2
• Potassium hydroxide microscopy provides rapid preliminary diagnosis 2
• Topical therapy alone is inadequate—oral therapy is required for both clinical and mycological cure 1, 2

Second-Line Options for Treatment Failure

If initial therapy fails, consider these factors first: poor compliance, suboptimal drug absorption, organism insensitivity, or reinfection 1, 2:

• If clinical improvement but positive mycology persists: Continue current therapy for an additional 2-4 weeks 1, 2
• If no clinical improvement: Switch to second-line therapy 1, 2

Second-Line Agents

Itraconazole is effective against both Trichophyton and Microsporum species 1, 2:

• Dosing: 5 mg/kg/day for 2-4 weeks or 50-100 mg/day for 4 weeks 2

Fluconazole is an alternative for refractory cases 2:

• Favorable tolerability profile and available in liquid form 2
• Particularly useful in younger children who cannot swallow tablets 4

Adjunctive Measures

Sporicidal shampoos reduce transmission and hasten spore eradication 2, 4:

• 2% ketoconazole or 1% selenium sulfide shampoo as adjunctive therapy 2, 4, 5
• Screen and treat family members and close contacts, especially for T. tonsurans infections 2

Treatment Endpoint and Monitoring

Mycological cure, not just clinical improvement, is the treatment endpoint 2:

• Repeat mycology sampling until clearance is documented 2
• Clinical relapse occurs if medication is discontinued before the organism is completely eradicated 3

Common Pitfalls to Avoid

• Do not use terbinafine for Microsporum infections—it has poor efficacy due to inadequate hair shaft penetration in children 1
• Do not rely on topical therapy alone—it cannot eradicate scalp infections 1, 2
• Do not stop treatment based solely on clinical improvement—continue until mycological cure is confirmed 2, 3
• Avoid underdosing griseofulvin—higher doses (15-20 mg/kg/day) are needed due to increasing treatment failures with lower doses 1, 4