What is the recommended treatment for ringworm in patients of various ages and medical histories?

Treatment of Ringworm (Tinea Corporis/Cruris/Pedis)

For ringworm of the body (tinea corporis) and groin (tinea cruris), apply topical terbinafine 1% cream once daily for 1 week, or topical azoles (clotrimazole 1% or miconazole 2%) twice daily for 2-4 weeks as first-line therapy. 1, 2, 3

First-Line Topical Treatment

For Tinea Corporis and Tinea Cruris (Body and Groin)

• Terbinafine 1% cream applied once daily for 1 week is the most convenient option with the shortest treatment duration 1, 4
• Clotrimazole 1% cream applied twice daily for 2-4 weeks is an effective alternative, demonstrating significantly higher mycological cure rates compared to placebo (RR 2.87, NNT 2) 2, 4
• Miconazole 2% cream applied twice daily for 2-4 weeks is another effective azole option 2, 4
• Naftifine 1% cream shows strong efficacy with mycological cure rates favoring it over placebo (RR 2.38, NNT 3) 4

For Tinea Pedis (Athlete's Foot)

• Between the toes: Apply terbinafine 1% cream twice daily for 1 week 1
• Bottom or sides of foot: Apply terbinafine 1% cream twice daily for 2 weeks 1
• Treatment duration for tinea pedis is generally 4 weeks with azoles or 1-2 weeks with allylamines 5

When to Use Oral Therapy

Oral antifungals are indicated when:

• Extensive disease is present 3
• Topical treatment has failed after 2 weeks 2
• Patient is immunocompromised 3
• Hair follicle involvement exists (tinea capitis) 3

Oral Treatment Options

• Oral fluconazole 150-200 mg weekly for 2-4 weeks for extensive or resistant cases 2, 6
• Terbinafine 250 mg daily for 1-2 weeks for tinea corporis/cruris or 2 weeks for tinea pedis 6
• Itraconazole 100 mg daily for 2 weeks or 200 mg daily for 7 days 6

Special Considerations for Tinea Capitis (Scalp Ringworm)

Tinea capitis requires systemic therapy, not topical treatment, because topical agents cannot penetrate the hair shaft. 7, 3, 8

First-Line Systemic Treatment by Weight

• Terbinafine dosing for Trichophyton species:

  • <20 kg: 62.5 mg per day for 2-4 weeks
  • 20-40 kg: 125 mg per day for 2-4 weeks

  • 40 kg: 250 mg per day for 2-4 weeks 7

• Griseofulvin for Microsporum species:

  • <50 kg: 15-20 mg/kg per day (maximum 500 mg) for 6-8 weeks

  • 50 kg: 1 g per day for 6-8 weeks 7

Second-Line for Tinea Capitis

• Itraconazole 5 mg/kg per day for 2-4 weeks if first-line therapy fails 7
• Fluconazole has demonstrated efficacy against T. violaceum, T. verrucosum, and M. canis 7

Critical Treatment Principles

Duration and Monitoring

• Continue treatment for at least 1 week after clinical clearing to prevent relapse 5
• The endpoint of treatment for tinea capitis is mycological cure, not just clinical improvement - repeat mycology sampling is recommended until clearance is achieved 7
• If no improvement after 2 weeks of appropriate topical therapy, switch to a different antifungal class or consider oral therapy 2

Common Pitfalls to Avoid

• Do NOT use combination antifungal-corticosteroid creams as first-line therapy - while they may show higher initial clinical cure rates, they are not recommended in clinical guidelines and can lead to complications including skin atrophy and potential resistance 3, 4
• Do NOT rely on clinical diagnosis alone - other conditions (eczema, psoriasis) can mimic ringworm; consider KOH preparation or culture for confirmation 3
• Do NOT use topical therapy for tinea capitis - systemic treatment is mandatory 3, 8

Treatment Failure Management

• Initially consider non-compliance, suboptimal drug absorption, organism resistance, or reinfection 7
• If clinical improvement with ongoing positive mycology: continue current therapy for 2-4 more weeks 7
• If no clinical improvement: switch to second-line therapy 7

Adjunctive Measures for Tinea Capitis

• Children receiving appropriate therapy should attend school or nursery 7
• Screen all family members and close contacts for T. tonsurans cases and treat positive cases 7
• Treat asymptomatic carriers with high spore load with systemic therapy 7

Comparative Effectiveness

There is no significant difference in mycological cure rates between azoles and benzylamines (RR 1.01), allowing choice based on cost, convenience, and patient preference 4. Terbinafine offers the advantage of once-daily application and shorter treatment duration (1 week for tinea corporis/cruris) compared to azoles (2-4 weeks) 1, 4, 5.