What is the recommended treatment for scalp fungus?

Treatment for Scalp Fungus (Tinea Capitis)

Oral antifungal therapy is mandatory for scalp fungus—topical therapy alone is ineffective and should never be used as monotherapy. 1

Diagnostic Confirmation Before Treatment

• Obtain scalp scrapings, hair plucks, brush samples, or swabs for microscopy and culture to identify the causative dermatophyte 1
• Start treatment immediately without waiting for culture results if cardinal clinical signs are present: scaling, lymphadenopathy, alopecia, or kerion formation 1
• Susceptibility testing is not indicated for dermatophytes 1

First-Line Oral Therapy: Species-Directed Approach

The choice of systemic antifungal must be guided by the causative organism or local epidemiology, as efficacy varies dramatically by species 1:

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

Terbinafine is superior for Trichophyton infections: 1

• < 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

Alternative - Griseofulvin (requires longer treatment): 1

• < 50 kg: 15-20 mg/kg/day for 6-8 weeks (may need 12-18 weeks for resistant Trichophyton)
• > 50 kg: 1 g daily for 6-8 weeks

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

Griseofulvin is superior for Microsporum infections: 1

• < 50 kg: 15-20 mg/kg/day for 6-8 weeks
• > 50 kg: 1 g daily for 6-8 weeks
• Take with fatty food to enhance absorption 1

Terbinafine is relatively ineffective for Microsporum because it cannot be incorporated into hair shafts in prepubertal children and does not reach the scalp surface where Microsporum arthroconidia are located 1

Critical Adjunctive Measures

• Use sporicidal shampoos (selenium sulfide 1%, ketoconazole 2%, or povidone-iodine) to reduce transmission of spores, though they cannot cure the infection alone 1, 2
• Apply shampoo 2-3 times weekly throughout treatment 2
• Screen and consider treating close household contacts who may be asymptomatic carriers 2

Treatment Failure Management

If no clinical improvement after initial treatment course: 1

1. First, assess compliance, drug absorption, and possibility of reinfection 1
2. If clinical improvement but positive mycology persists: Continue current therapy for additional 2-4 weeks 1
3. If no initial clinical improvement: Switch to second-line therapy

Second-Line Therapy

Itraconazole (effective against both Trichophyton and Microsporum): 1

• 5 mg/kg/day (specific duration varies by organism)
• Safe and effective alternative when first-line agents fail 1

Special Considerations

Kerion (Inflammatory Mass)

• Start oral antifungal therapy immediately 1
• Consider short course of oral or topical corticosteroids for severe cases, though evidence is mixed 3
• Kerions require the same antifungal duration as non-inflammatory tinea capitis 3

Contraindications to Griseofulvin

• Lupus erythematosus, porphyria, severe liver disease 1
• Drug interactions: rifampicin decreases levels; cimetidine increases levels 1

Monitoring

• Liver enzyme monitoring is generally unnecessary for treatment courses ≤4 weeks 3
• Gastrointestinal disturbances and rashes occur in <8% with terbinafine; only 0.8% require discontinuation 1

Common Pitfalls to Avoid

• Never use topical therapy alone—it cannot penetrate hair shafts and will fail 1
• Do not use terbinafine for Microsporum infections—it has poor efficacy and high failure rates 1, 4
• Do not underdose griseofulvin—higher doses (20-25 mg/kg/day) may be needed for Trichophyton due to increasing treatment failures 3
• Do not stop treatment prematurely—complete the full course even if symptoms improve early 1