Treatment for Ringworm
For ringworm (tinea corporis, tinea cruris, tinea pedis), topical antifungal therapy is the first-line treatment for localized infections, with systemic therapy reserved for extensive disease, scalp involvement, or treatment failures. 1, 2
Topical Therapy for Localized Infections
Topical antifungals are highly effective for limited skin infections and should be applied for 2-4 weeks depending on the site. 2, 3
- Terbinafine cream is one of the most effective topical agents, requiring only 1-2 weeks of treatment compared to 2-4 weeks for azoles 2, 3
- Azole antifungals (clotrimazole, miconazole, ketoconazole) applied twice daily are effective alternatives, with clotrimazole showing significantly higher cure rates than placebo (NNT 2) 3
- Naftifine 1% demonstrates strong efficacy with mycological cure rates significantly better than placebo (NNT 3) 3
Treatment Duration by Site
- Tinea corporis and tinea cruris: 2 weeks of topical therapy 2
- Tinea pedis: 4 weeks with azoles or 1-2 weeks with allylamines (terbinafine, naftifine) 2
- Continue treatment for at least 1 week after clinical clearing to prevent relapse 2
Systemic Therapy Indications
Oral antifungal therapy is required when topical treatment fails, infection is extensive, or specific sites are involved (scalp, nails, beard). 1, 4
When to Use Systemic Therapy
- Tinea capitis (scalp ringworm) - topical therapy alone is inadequate 4, 5
- Tinea barbae (beard area) - requires systemic treatment 6, 1
- Tinea unguium (nail infections) 1
- Widespread or resistant tinea corporis/cruris 1
- Immunocompromised patients 7
Systemic Treatment Options
Griseofulvin remains the only FDA-approved systemic treatment for dermatophyte infections in children, though newer agents are increasingly used off-label. 1, 4
Griseofulvin Dosing (FDA-Approved)
- Adults: 500 mg daily (can give as 125 mg four times daily, 250 mg twice daily, or 500 mg once daily) 1
- Severe infections: May start with 750 mg to 1 g daily, then reduce to 500 mg after response 1
- Children >2 years: 10 mg/kg daily (children 30-50 lbs: 125-250 mg daily; >50 lbs: 250-500 mg daily) 1
Treatment Duration with Griseofulvin
- Tinea capitis: 4-6 weeks 1
- Tinea corporis: 2-4 weeks 1
- Tinea pedis: 4-8 weeks 1
- Fingernails: At least 4 months 1
- Toenails: At least 6 months 1
Alternative Systemic Agents (Off-Label for Most Indications)
- Terbinafine: Requires only 6 weeks for tinea capitis versus 6-8 weeks with griseofulvin 4
- Fluconazole 150-200 mg once daily for 2-4 weeks for extensive or severe fungal infections including tinea barbae 6
- Itraconazole and fluconazole: Offer shorter treatment intervals with acceptable safety profiles 5
Critical Pitfalls to Avoid
Do not use topical corticosteroid-antifungal combinations for more than 2 weeks, and never use them in children under 12 years, on the face, or in occluded areas. 7
- While combination products may provide faster symptom relief in heavily inflamed lesions, the corticosteroid can suppress local immunity and allow dermatophytes to persist or invade deeper 7
- If using a combination product: Switch to pure antifungal once symptoms improve, limit to 2 weeks for tinea cruris and 4 weeks for tinea pedis/corporis 7
- Contraindications for steroid combinations: Children <12 years, facial lesions, diaper areas, immunosuppressed patients 7
Diagnostic Confirmation Required
Always confirm dermatophyte infection with KOH preparation, fungal culture, or histology before initiating systemic therapy. 1
- Griseofulvin is ineffective against Candida, bacteria, and other non-dermatophyte fungi 1
- The drug should not be used for "minor or trivial" infections that respond to topical agents alone 1
Adjunctive Measures
Concomitant topical therapy and hygiene measures are essential to control reinfection sources, particularly for tinea pedis. 1