Antifungal Treatment Plan for Tinea and Dermatophytes
Treatment Strategy by Site of Infection
The treatment approach for dermatophyte infections depends critically on the anatomical site involved, with scalp and nail infections requiring systemic therapy while most skin infections can be managed topically.
Tinea Capitis (Scalp)
Organism-directed therapy is essential for optimal outcomes in tinea capitis, with terbinafine preferred for Trichophyton species and griseofulvin for Microsporum species. 1
First-Line Systemic Treatment
For Trichophyton species infections: Terbinafine is the preferred agent due to its fungicidal activity and superior efficacy, with weight-based dosing: 1
For Microsporum species infections: Griseofulvin is the preferred agent, as terbinafine fails against Microsporum because it cannot be incorporated into hair shafts in prepubertal children 1
When to Start Treatment Empirically
- Begin treatment before mycology results if cardinal clinical signs are present, including scale, lymphadenopathy, alopecia, or kerion 1
- Always collect specimens via scalp scrapings, hair pluck, brush, or swab for microscopy and culture before starting therapy 1
Second-Line Options
- Itraconazole: 5 mg/kg/day for 2-4 weeks or 50-100 mg/day for 4 weeks, effective against both Trichophyton and Microsporum species 1
- Fluconazole: Consider for refractory cases, with favorable tolerability profile and availability in liquid form 1
Adjunctive Measures
- Topical antifungal shampoo should be used as adjunctive therapy to reduce spore shedding 1
- Screen and treat family members and close contacts, especially for T. tonsurans infections, as over 50% may be affected 3
- Clean all fomites (hairbrushes, combs, towels) with 2% sodium hypochlorite solution or disinfectant 1, 3
Tinea Corporis, Cruris, and Pedis (Body, Groin, Feet)
Most localized skin infections respond to topical antifungal therapy, reserving oral agents for extensive disease, treatment failure, or immunocompromised patients. 4
First-Line Topical Treatment
- Terbinafine cream or butenafine cream applied once or twice daily for 2-4 weeks for tinea corporis and cruris 4
- For tinea pedis, extend treatment duration to 4-6 weeks 5
- These agents are effective against dermatophytes, yeasts, and Malassezia furfur 5
Indications for Oral Therapy
- Extensive disease involving large body surface area 5
- Failed topical treatment after appropriate duration 3
- Immunocompromised patients 6
- Severe moccasin-type tinea pedis 4
Oral Treatment Options When Indicated
- Itraconazole: 100 mg daily for 15 days (87% mycological cure rate) 3
- Terbinafine: 250 mg daily for 1-2 weeks, particularly effective against T. tonsurans 3
Tinea Unguium (Onychomycosis)
Oral antifungal therapy is the treatment of choice for onychomycosis, with terbinafine generally preferred over itraconazole due to superior efficacy and shorter treatment duration. 7
First-Line Oral Treatment
Terbinafine: 250 mg daily is first-line for dermatophyte onychomycosis 7, 8
Itraconazole: Alternative first-line option 7
Second-Line Options
- Fluconazole: 150-450 mg weekly for 3 months (fingernails) or at least 6 months (toenails) 7
- Griseofulvin: Lower efficacy and higher relapse rates; 500-1000 mg daily for 6-9 months (fingernails) or 12-18 months (toenails) 7
Topical Therapy
- Amorolfine 5% lacquer: Useful for superficial and distal onychomycosis, applied once or twice weekly 7
- Combination treatment with oral and topical therapy recommended if response to topical monotherapy alone is likely to be poor 7
Critical Monitoring and Follow-Up
The definitive endpoint for adequate treatment must be mycological cure, not just clinical response. 7
- Repeat mycology sampling at the end of standard treatment period and then monthly until mycological clearance is documented 7
- Treatment should be tailored to each individual patient according to response 7
- For tinea capitis, children can return to school once appropriate systemic and adjuvant topical therapy has been commenced 7
Prevention of Recurrence
- Always wear protective footwear in public bathing facilities, gyms, and hotel rooms to avoid re-exposure to T. rubrum 7
- Apply antifungal powders (miconazole, clotrimazole, or tolnaftate) in shoes and on feet 7
- Wear cotton, absorbent socks and keep nails as short as possible 7
- Discard old footwear or treat with naphthalene mothballs in sealed plastic bags for minimum 3 days 7
- Treat all infected family members simultaneously, as both onychomycosis and tinea pedis are contagious 7
Common Pitfalls to Avoid
- Never use terbinafine for Microsporum infections due to poor efficacy in prepubertal children 1
- Never rely on topical therapy alone for scalp or nail infections, as it cannot eradicate these infections 1
- Avoid underdosing griseofulvin, as higher doses (20-25 mg/kg/day) are needed due to increasing treatment failures with lower doses 1
- Do not stop treatment based on clinical improvement alone—always confirm mycological cure 7
- Monitor liver function with terbinafine and itraconazole, especially in patients with pre-existing hepatic abnormalities or prolonged therapy 7, 8
Important Safety Considerations
- Terbinafine: Risk of hepatotoxicity (obtain pretreatment transaminases), taste disturbance (may be permanent), smell disturbance, depressive symptoms, and severe neutropenia 8
- Itraconazole: Contraindicated in heart failure; significant drug interactions with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin 7, 3
- Griseofulvin: Should be taken with fatty food to increase absorption 7