Management of Tinea Infections
Treatment Strategy Based on Anatomical Site
The treatment approach for tinea infections depends critically on the anatomical location, with scalp and nail infections requiring systemic therapy while most skin infections can be managed topically. 1
Tinea Capitis (Scalp Infections)
Organism-Directed Therapy
The choice of systemic antifungal should be guided by the causative organism 1:
For Trichophyton species (including T. tonsurans): Terbinafine is the preferred agent 1
For Microsporum species (including M. canis): Griseofulvin is the preferred agent 1, 2
Diagnostic Confirmation
- Obtain mycological confirmation through KOH microscopy and fungal culture before initiating therapy whenever possible 1
- Collect specimens by scalp scraping, hair pluck, brush sampling, or swab 1, 3
- Start treatment immediately without waiting for culture results if kerion, severe scaling, lymphadenopathy, or alopecia are present 1
Special Considerations for Kerion
- Kerion represents a delayed inflammatory host response, not bacterial infection 1
- Do not delay systemic antifungal therapy 1
- Topical or oral corticosteroids may provide symptomatic relief for severe inflammation 1
Tinea Corporis, Cruris, and Pedis (Skin Infections)
Topical Therapy for Localized Disease
Most localized skin infections respond to topical antifungal therapy, with treatment duration of 2-4 weeks for tinea corporis/cruris and 4 weeks for tinea pedis. 1, 4
- Continue treatment for at least one week after clinical clearing of infection 4
- Topical azoles or allylamines are effective first-line options 4
Systemic Therapy Indications
- Extensive disease
- Treatment failure with topical therapy
- Immunocompromised patients
- Infections resistant to topical treatment
Oral therapy options:
- Itraconazole: 100 mg daily for 15 days (87% mycological cure rate) 1, 5
- Terbinafine: 250 mg daily for 1-2 weeks, particularly effective against T. tonsurans 1, 5
Tinea Unguium (Nail Infections)
Systemic Therapy Required
Oral antifungal therapy is the treatment of choice for onychomycosis, with terbinafine generally preferred over itraconazole due to superior efficacy and shorter treatment duration. 1
First-Line Treatment: Terbinafine
Alternative: Itraconazole
- Continuous therapy: 200 mg daily for 12 weeks 1
- Pulse therapy: 400 mg daily for 1 week per month 1
- 2 pulses for fingernails
- 3 pulses for toenails
Critical Monitoring and Follow-Up
The definitive endpoint for adequate treatment must be mycological cure, not just clinical response. 1, 5
- Perform repeat mycology sampling at the end of standard treatment period 1
- Continue monthly sampling until mycological clearance is documented 1
- Monitor liver function with terbinafine and itraconazole, especially in patients with pre-existing hepatic abnormalities or prolonged therapy 1
Prevention of Recurrence
Environmental Measures
- Always wear protective footwear in public bathing facilities, gyms, and hotel rooms 1
- Apply antifungal powders (miconazole, clotrimazole, or tolnaftate) in shoes and on feet 1
- Clean contaminated combs and brushes with disinfectant or 2% sodium hypochlorite solution 5
Household Screening
- Screen and treat all family members, especially with anthropophilic species like T. tonsurans, as over 50% of family members may be affected 5
- Avoid sharing towels, combs, hats, and other personal items 3
Important Safety Considerations and Drug Interactions
Itraconazole Contraindications and Interactions
- Contraindicated in heart failure 1
- Significant drug interactions with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin 1, 5
- Licensed for children over 12 years in the UK, though used off-label in younger children in some countries 5
Common Pitfalls to Avoid
- Do not discontinue antifungal therapy if dermatophytid reactions occur (these represent a cell-mediated host response to dying dermatophytes; treat symptomatically with topical corticosteroids) 1
- Do not rely solely on clinical improvement; always confirm mycological cure 1, 5
- Resistance development is rare, and susceptibility testing is not usually needed 1