What is the recommended management of tinea capitis?

Management of Tinea Capitis

Tinea capitis requires oral antifungal therapy tailored to the causative organism: terbinafine for Trichophyton species (2-4 weeks) and griseofulvin for Microsporum species (6-8 weeks), with topical therapy serving only as an adjunct to reduce spore transmission. 1

Diagnostic Confirmation

Obtain mycological specimens before starting treatment whenever possible, but do not delay therapy if cardinal clinical signs are present (kerion, severe scaling, lymphadenopathy, or alopecia). 1, 2

• Collect specimens via scalp scrapings, hair plucking, brush sampling (cytobrush), or gauze swabs 3
• Use potassium hydroxide (10-30%) preparation for rapid microscopic diagnosis 2
• Culture on Sabouraud agar with cycloheximide for at least 2 weeks (3 weeks if T. verrucosum suspected from cattle exposure) 2
• Wood's lamp examination can identify M. canis infections through fluorescence 3
• Dermoscopy may reveal "comma-shaped" hairs in white children with ectothrix infection or corkscrew hairs in Afro-Caribbean children 3

First-Line Treatment Algorithm

For Trichophyton Species Infections

Terbinafine is the preferred agent due to its fungicidal activity, superior efficacy, and shorter treatment duration. 1

Weight-based dosing: 1, 2

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

Advantages: Shorter treatment duration improves compliance, with gastrointestinal disturbances and rashes occurring in less than 8% of children 1

For Microsporum Species Infections

Griseofulvin is the preferred and only reliably effective agent for Microsporum infections. 1, 4

Dosing: 1, 2, 5

• Children <50 kg: 15-20 mg/kg/day for 6-8 weeks
• Children >50 kg and adults: 1 g/day for 6-8 weeks
• Administer in divided doses (125 mg four times daily, 250 mg twice daily, or 500 mg once daily) 5

Critical pitfall: Terbinafine fails against Microsporum species because it cannot be incorporated into hair shafts in prepubertal children and doesn't reach the scalp surface where arthroconidia are located 1. Eight weeks of griseofulvin is significantly more effective than 4 weeks of terbinafine for confirmed Microsporum infection 1, 4

When Organism is Unknown

Start treatment empirically before mycology results if any cardinal clinical signs are present. 1

• In North America and urban areas where T. tonsurans predominates, start with terbinafine 6, 7
• In areas where M. canis is common (Asian countries, rural areas with animal exposure), start with griseofulvin 4
• Switch therapy once culture results identify the organism 1

Second-Line Treatment Options

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

Itraconazole

• Dosing: 5 mg/kg/day for 2-4 weeks or 50-100 mg/day for 4 weeks 1
• Effective against both Trichophyton and Microsporum species 1, 8
• Important drug interactions: Enhanced toxicity with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, cisapride, and simvastatin 2
• Contraindicated in heart failure 2

Fluconazole

• Alternative for refractory cases with favorable tolerability profile 1
• Available in liquid form, which may improve compliance in children 1

Treatment Failure Algorithm

• 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

Adjunctive Topical Therapy

Topical antifungals are mandatory as adjunctive treatment but never as monotherapy, as they cannot eradicate scalp infections. 1, 9

• Use 2% ketoconazole or 1% selenium sulfide shampoo to reduce spore transmission 6, 9
• Apply topical antifungals to affected areas while on systemic therapy 1

Special Clinical Variants

Kerion Management

Kerion represents a delayed inflammatory host response to dermatophytes, not bacterial infection—do not delay systemic antifungal therapy. 3, 2

• Start oral antifungals immediately 2
• Add topical or oral corticosteroids for symptomatic relief of severe inflammation 3, 2
• Do not misdiagnose as bacterial abscess, though secondary bacterial infection should not be overlooked 3

Dermatophytid Reactions

Pruritic papular eruptions ("id" reactions) may occur after treatment initiation—these represent a cell-mediated host response to dying dermatophytes and do not warrant cessation of antifungal therapy. 3, 2

• Treat symptomatically with topical corticosteroids (or occasionally oral if very severe) 3, 2
• Continue systemic antifungal therapy 3, 2

Favus

• Chronic inflammatory variant typically caused by T. schoenleinii 3
• Characterized by yellow, crusted, cup-shaped lesions ("scutula") that may result in cicatricial alopecia 3
• Fluoresces under Wood's lamp 3

Treatment Endpoint and Monitoring

The definitive endpoint is mycological cure (negative microscopy and culture), not clinical improvement alone. 1, 2

• Repeat mycology sampling at the end of standard treatment period 1, 2
• Continue monthly sampling until mycological clearance is documented 1, 2
• Clinical relapse will occur if medication is not continued until the infecting organism is eradicated 5

Infection Control Measures

Screen and treat all family members and close contacts, especially for T. tonsurans infections. 1, 2

• Cleanse hairbrushes and combs with bleach or 2% sodium hypochlorite solution 1
• Avoid sharing personal items (combs, brushes, hats, pillows) 2
• Children receiving appropriate systemic and adjunctive topical therapy can attend school or nursery—exclusion is impractical and unnecessary 1

Common Pitfalls to Avoid

• Never use topical therapy alone—it cannot eradicate scalp infections as topical agents do not penetrate hair follicles deep within the dermis 1, 8, 9
• Never use terbinafine for Microsporum infections—it has poor efficacy and will lead to treatment failure 1, 4
• Avoid underdosing griseofulvin—higher doses (15-20 mg/kg/day) are needed due to increasing treatment failures with lower doses 1
• Do not stop treatment based on clinical improvement alone—continue until mycological cure is achieved 1, 2, 5
• Do not discontinue antifungals for dermatophytid reactions—these are expected immune responses, not drug allergies 3, 2