Treatment of Ringworm (Tinea Infections)
For uncomplicated ringworm of the body (tinea corporis) or groin (tinea cruris), apply topical azole antifungals (clotrimazole or miconazole cream) twice daily for 2-4 weeks as first-line treatment. 1
Topical Therapy for Localized Infections
When to use topical treatment alone:
- Limited skin involvement without hair follicle or nail involvement 2
- Tinea corporis (body ringworm) 1, 3
- Tinea cruris (groin/jock itch) 1, 3
- Tinea pedis (athlete's foot) 2
Specific topical options:
- Azoles (clotrimazole or miconazole 1%): Apply twice daily for 2-4 weeks 1, 3
- Terbinafine cream: Highly effective with clinical cure rates 4.5 times higher than placebo 3
- Naftifine 1%: Apply once or twice daily, with mycological cure rates 2.4 times higher than placebo 3
- Nystatin cream: Alternative if azoles are not tolerated 1
Critical adjunctive measures:
- Keep infected areas dry throughout treatment, as moisture promotes fungal growth 1
- Address predisposing factors including diabetes, immunosuppression, or excessive moisture 1
- Continue topical agents as needed, particularly for tinea pedis where yeasts and bacteria may coexist 4
Oral Therapy - When to Escalate
Mandatory indications for systemic treatment:
- Tinea capitis (scalp ringworm): Topical therapy alone is ineffective; systemic treatment is required 5, 6
- Tinea unguium (nail infections): Oral therapy necessary due to poor topical penetration 4
- Tinea barbae (beard area): Hair follicle involvement requires systemic treatment 4
Optional indications for systemic treatment:
- Extensive disease involving large body surface areas 2
- Failure of topical therapy after 2-4 weeks 1, 2
- Immunocompromised patients 2
- Hair follicle involvement in any location 2
First-Line Oral Antifungal Agents
Terbinafine (preferred for most systemic infections):
- Tinea capitis: Well-tolerated, effective, and inexpensive first-line option requiring 6 weeks of treatment 5, 2
- Onychomycosis: First-line therapy due to superior efficacy profile 2
- Limitation: Increasingly ineffective against emerging Trichophyton indotineae infections due to squalene epoxidase gene mutations 7
Griseofulvin (FDA-approved for dermatophyte infections):
- Dosing: Adults 500 mg daily (or 125 mg four times daily); children >2 years: 10 mg/kg daily 4
- Duration by site: 4
- Tinea capitis: 4-6 weeks
- Tinea corporis: 2-4 weeks
- Tinea pedis: 4-8 weeks
- Fingernail infections: minimum 4 months
- Toenail infections: minimum 6 months
- Note: Only griseofulvin is FDA-approved specifically for tinea capitis in children, though newer agents show similar efficacy 5, 6
Fluconazole:
- Dosing: 100-200 mg daily for 7-14 days for moderate to severe cutaneous candidiasis 1
- Indication: Extensive or severe infections, or failure of topical therapy 1
- Limitation: Generally not effective against emerging resistant strains 7
Emerging Resistant Infections (Trichophyton indotineae)
Recognition: Suspect when infections fail to respond to standard terbinafine therapy, particularly in patients with travel history to the Indian subcontinent 7
Treatment approach for resistant infections:
- Itraconazole: 200 mg daily or higher for extended duration as primary alternative 7
- Topical non-allylamine antifungals: Consider for small areas, either as monotherapy or combined with oral therapy 7
- Salvage therapy: Off-label voriconazole or posaconazole when both terbinafine and itraconazole fail 7
Critical Treatment Principles
Diagnostic confirmation before treatment:
- Identify dermatophyte by direct microscopy (KOH preparation) or fungal culture before initiating therapy 4
- Clinical diagnosis alone is unreliable as eczema, psoriasis, and dystrophic nails can mimic tinea 2
Duration and monitoring:
- Continue medication until the infecting organism is completely eradicated by clinical or laboratory examination 4
- Premature discontinuation leads to clinical relapse 4
- Concomitant topical agents usually required, particularly for tinea pedis 4
Avoid combination steroid-antifungal products: