What is the recommended management for tinea capitis (scalp ringworm)?

Treatment of Scalp Ringworm (Tinea Capitis)

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

Diagnostic Confirmation Before Treatment

• Collect scalp specimens via scrapings, hair pluck, brush sampling, or swab for microscopy and culture to identify the causative organism 1
• Potassium hydroxide (KOH) preparation provides rapid preliminary diagnosis 1
• Start treatment empirically before mycology results if cardinal clinical signs are present: scale, lymphadenopathy, alopecia, or kerion 1
• Wood's lamp examination detects Microsporum canis infections through characteristic fluorescence 1
• Dermoscopy shows "comma-shaped" hairs in ectothrix infections (white children) or corkscrew hairs (Afro-Caribbean children) 1

First-Line Treatment Selection Based on Organism

For Trichophyton Species (Most Common in North America)

Terbinafine is the preferred first-line agent due to superior efficacy and shorter treatment duration: 1

• <20 kg: 62.5 mg/day for 2-4 weeks 1, 2
• 20-40 kg: 125 mg/day for 2-4 weeks 1, 2
• >40 kg: 250 mg/day for 2-4 weeks 1, 2
• Achieves >80% mycological cure for Trichophyton species 1
• Gastrointestinal disturbances and rashes occur in <8% of children 1
• Critical pitfall: Terbinafine fails against Microsporum species (only 67.9% response rate) because it cannot be incorporated into hair shafts in prepubertal children 1, 2

For Microsporum Species

Griseofulvin is the preferred first-line agent and remains the only licensed treatment in many countries: 1, 2

• <50 kg: 15-20 mg/kg/day for 6-8 weeks 1, 2
• >50 kg: 1 g/day for 6-8 weeks 1, 2, 3
• Achieves 88.5% response rate for Microsporum species 2
• Must be given for the full 6-8 weeks—underdosing or premature discontinuation leads to treatment failure 1
• Take with fatty meal to enhance absorption 1
• Contraindicated in lupus erythematosus, porphyria, and severe liver disease 4

Second-Line Options for Treatment Failure

If initial therapy fails, consider poor compliance, suboptimal absorption, organism insensitivity, or reinfection: 1

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

Itraconazole (Effective Against Both Trichophyton and Microsporum)

• 50-100 mg/day for 4 weeks or 5 mg/kg/day for 2-4 weeks 1, 2
• Achieves 87% mycological cure rate 4
• Monitor for drug interactions with warfarin, antihistamines, antipsychotics, midazolam, digoxin, and simvastatin 4

Fluconazole (Alternative for Refractory Cases)

• Favorable tolerability profile with availability in liquid form for younger children 1, 5
• Particularly useful when compliance is an issue 5

Management of Inflammatory Variants

Kerion (Inflammatory Mass)

• Initiate oral antifungal therapy immediately without awaiting culture results 1
• Add topical or oral corticosteroids to alleviate severe inflammatory symptoms 1
• Recognize that kerion is a fungal-driven inflammatory response, not a bacterial abscess, though secondary bacterial infection should be evaluated when clinically indicated 1

Dermatophytid (Id) Reaction

• Pruritic papular eruptions after antifungal initiation represent cell-mediated response to dying dermatophytes 1
• Do not discontinue systemic antifungal therapy 1
• Provide symptomatic relief with topical corticosteroids (or oral steroids in severe cases) while continuing antifungal treatment 1

Favus (Chronic Variant)

• Caused by Trichophyton schoenleinii with characteristic yellow, cup-shaped crusted lesions ("scutula") 1
• Can lead to permanent scarring (cicatricial) alopecia if untreated 1

Adjunctive Measures to Prevent Transmission

• Use topical antifungal shampoo (selenium sulfide or ketoconazole 2%) as adjunctive therapy only—never as monotherapy 1, 6
• Screen and treat all family members and close contacts, especially for T. tonsurans infections where >50% of household contacts may be affected 1, 4
• Clean hairbrushes and combs with bleach or 2% sodium hypochlorite solution 1
• Avoid sharing towels, combs, or personal items 4

Monitoring and Treatment Endpoint

Mycological cure, not clinical improvement, is the definitive treatment endpoint: 1, 2

• Repeat mycology sampling until clearance is documented 1
• Monitor for treatment side effects, though serious adverse events are rare (0.04% incidence) 4
• Children receiving appropriate systemic and adjunctive topical therapy can attend school or nursery—exclusion is unnecessary 1, 2

Common Pitfalls to Avoid

• Never use topical therapy alone—it cannot eradicate scalp infections 1
• Never use terbinafine for Microsporum infections—efficacy is poor 1
• Never underdose griseofulvin—higher doses (15-20 mg/kg/day) are needed due to increasing treatment failures with lower doses 1, 5
• Never stop treatment based on clinical improvement alone—continue until mycological cure is achieved 1