What is the primary treatment for a patient diagnosed with tinea capitis favus?

Treatment of Tinea Capitis Favus

Griseofulvin is the treatment of choice for tinea capitis favus, given at 15-20 mg/kg/day for 6-8 weeks in children under 50 kg, or 1 g/day for 6-8 weeks in children over 50 kg and adults. 1, 2

Why Griseofulvin for Favus

• Favus is caused by T. schoenleinii, a Trichophyton species that responds well to griseofulvin, making it the preferred first-line agent for this specific variant of tinea capitis 1, 3
• Griseofulvin is FDA-approved for tinea capitis and has an excellent long-term safety record spanning decades of use 2, 4
• The drug must be continued for the full 6-8 week course because favus is a chronic, inflammatory infection that can result in cicatricial (scarring) alopecia if inadequately treated 1

Dosing Algorithm

For children under 50 kg:

• Give 15-20 mg/kg/day divided into doses (can be given as 125 mg four times daily, 250 mg twice daily, or as a single daily dose) for 6-8 weeks 1, 3, 2

For children over 50 kg and adults:

• Give 1 g/day (can be divided as 250 mg four times daily or 500 mg twice daily) for 6-8 weeks 1, 3, 2

Higher doses may be needed for severe or extensive disease:

• Start with 0.75-1.0 g/day in adults, then reduce gradually to 0.5 g after response is noted 2

Alternative Agents (Second-Line)

If griseofulvin fails or is not tolerated, consider:

• Terbinafine: Weight-based dosing for 2-4 weeks (children <20 kg: 62.5 mg/day; 20-40 kg: 125 mg/day; >40 kg: 250 mg/day), though this is more effective for other Trichophyton species than for chronic favus 1, 3
• Itraconazole: 5 mg/kg/day for 2-4 weeks, effective against Trichophyton species including T. schoenleinii 1, 3
• Fluconazole: Can be used for refractory cases, though less cost-effective and not licensed for children under 10 years in the UK 1, 3

Critical Adjunctive Measures

Topical antifungal shampoos are mandatory as adjunctive therapy:

• Use selenium sulfide or ketoconazole shampoo to reduce spore viability and prevent transmission 1, 4, 5
• Apply twice weekly throughout the treatment course 1

Screen and treat all family members and close contacts:

• More than 50% of family members may harbor infection, often asymptomatically 1
• Failure to treat household contacts results in high recurrence rates 1

Cleanse all fomites:

• Disinfect hairbrushes, combs, and towels with 2% sodium hypochlorite solution or bleach 1, 3
• Viable spores can persist on these items and cause reinfection 1

Monitoring and Treatment Endpoints

The endpoint is mycological cure, not clinical improvement:

• Repeat mycology sampling (scalp scraping, hair pluck, or brush) at the end of treatment 1, 3
• Continue monthly sampling until microscopy and culture are negative 1, 3
• Clinical improvement without mycological clearance will result in relapse 1, 2

Baseline and monitoring laboratory tests:

• Obtain baseline liver function tests before starting griseofulvin, especially if pre-existing hepatic abnormalities exist 6
• Monitoring during treatment is generally unnecessary for standard 6-8 week courses 5

Special Considerations for Favus

Favus fluoresces under Wood's lamp:

• Use Wood's lamp examination to identify affected hairs for targeted sampling 1
• This distinguishes favus from other tinea capitis variants 1

Watch for cicatricial alopecia:

• Favus can cause permanent scarring alopecia if treatment is delayed or inadequate 1
• Early diagnosis and complete mycological cure are essential to prevent this complication 1

Corticosteroids may be needed for severe inflammation:

• If severe inflammatory response develops, topical or oral corticosteroids provide symptomatic relief 1, 5
• Do not discontinue antifungal therapy when adding corticosteroids 1

Common Pitfalls to Avoid

• Never use topical antifungals alone—they cannot penetrate the hair shaft and will fail to eradicate infection 1, 3
• Do not stop treatment when clinical improvement occurs—continue until mycological cure is documented to prevent relapse 1, 2
• Do not underdose griseofulvin—use 15-20 mg/kg/day, not lower doses, as treatment failures are increasing with suboptimal dosing 3
• Do not confuse favus with bacterial abscess—the yellow crusted scutula are fungal, not bacterial, though secondary bacterial infection can occur 1

School Attendance

Children on appropriate systemic and topical therapy can attend school:

• Exclusion from school is impractical and unnecessary once treatment is initiated 1, 3
• Ensure compliance with both oral antifungal and adjunctive topical therapy 1