What is the recommended treatment for ringworm (tinea infection)?

Treatment of Ringworm (Tinea Infections)

For most ringworm infections of the body (tinea corporis) and groin (tinea cruris), topical antifungal therapy is the first-line treatment, while scalp infections (tinea capitis) and nail infections (tinea unguium) require oral antifungal agents.

Topical Treatment for Tinea Corporis and Tinea Cruris

Apply topical antifungal agents once or twice daily for 2-4 weeks, continuing for at least one week after clinical resolution to prevent relapse. 1

First-Line Topical Agents:

• Terbinafine 1% cream - Apply once or twice daily for 1-2 weeks 1
• Naftifine 1% cream - Apply once or twice daily for 2-4 weeks 1
• Azole antifungals (clotrimazole, miconazole, ketoconazole) - Apply twice daily for 2-4 weeks 1

Terbinafine and naftifine demonstrate superior efficacy compared to placebo, with number needed to treat of 3 for clinical cure. 1 Azoles are equally effective but may require slightly longer treatment duration. 1

When Topical Therapy Fails:

Consider oral antifungal therapy if: 2, 3

• Extensive disease involving large body surface areas
• Hyperkeratotic lesions unresponsive to topical monotherapy
• Involvement of hair follicles
• Immunocompromised patients
• Lesions near eyes, ears, or mouth where topical application is difficult

Oral Treatment for Tinea Capitis

Oral antifungal therapy is mandatory for scalp ringworm; topical agents alone are ineffective because the infection involves hair follicles. 4, 2

First-Line Oral Therapy:

Griseofulvin remains the only FDA-licensed treatment for tinea capitis in children in the UK and US: 4, 5

• Dosage: 20-25 mg/kg/day for 6-8 weeks (up to 1g/day in adults) 4, 5
• Take with fatty food to enhance absorption 4
• Continue until mycological cure is confirmed 4, 5

Terbinafine is highly effective and increasingly preferred despite being unlicensed for this indication in some regions: 4, 3

• Weight-based dosing:
  • <20 kg: 62.5 mg/day for 2-4 weeks
  • 20-40 kg: 125 mg/day for 2-4 weeks

  • 40 kg: 250 mg/day for 2-4 weeks 4

Treatment selection depends on the causative organism - Trichophyton species respond better to terbinafine (2-4 weeks), while Microsporum species require griseofulvin (6-8 weeks). 4

Second-Line Options:

• Itraconazole: 5 mg/kg/day for 2-4 weeks (effective against both Trichophyton and Microsporum) 4
• Fluconazole: 6 mg/kg/day for 2-4 weeks (effective but more expensive) 4

Adjunctive Measures:

• Use antifungal shampoos (ketoconazole 2%, selenium sulfide 1%, or povidone-iodine) to reduce spore transmission 4
• Screen and treat household contacts for Trichophyton tonsurans infections 4
• Allow children to attend school during treatment - isolation is unnecessary 4

Oral Treatment for Tinea Unguium (Onychomycosis)

Oral antifungal therapy is required for nail infections; topical therapy alone is inadequate. 3, 6

First-Line Therapy:

Terbinafine 250 mg once daily for 12 weeks (fingernails) or 12-16 weeks (toenails) is the most effective and cost-efficient treatment. 3, 6

Alternative Regimens:

• Itraconazole pulse therapy: 200 mg twice daily for 1 week per month × 2 pulses (fingernails) or 3-4 pulses (toenails) 6
• Fluconazole: 150-300 mg once weekly for 9-18 months until abnormal nail grows out 6

Griseofulvin is no longer recommended for onychomycosis due to poor efficacy and prolonged treatment duration (4-6 months for fingernails, 6+ months for toenails). 5, 6

Special Considerations

Tinea Barbae (Beard Area):

Fluconazole 150-200 mg once daily for 2-4 weeks is recommended for extensive or severe fungal infections of the beard. 7

Combination Antifungal-Steroid Products:

Avoid combination antifungal-corticosteroid creams as routine therapy. 3 While they may provide faster symptom relief initially, they can mask the infection, promote fungal resistance, and cause skin atrophy with prolonged use. 3 Reserve for cases with severe inflammation under specialist guidance.

Hyperkeratotic Tinea Pedis:

Combine oral and topical antifungal therapy for thick, scaly foot infections unresponsive to topical treatment alone. 2

Common Pitfalls to Avoid

• Never treat without confirming diagnosis - Obtain KOH preparation, fungal culture, or biopsy before starting therapy, as eczema, psoriasis, and other conditions mimic tinea 3
• Do not stop treatment at clinical improvement - Continue until mycological cure is documented to prevent relapse 4, 5
• Avoid topical steroids alone - They worsen fungal infections and can lead to "tinea incognito" 3
• Do not use griseofulvin for Candida or non-dermatophyte infections - It is ineffective against these organisms 5

Monitoring and Follow-Up

Repeat mycological sampling (KOH or culture) is recommended until clearance is achieved, particularly for tinea capitis and onychomycosis. 4 Clinical appearance alone is unreliable for determining cure. 3

Treatment failure should prompt consideration of: 4

• Non-compliance or inadequate drug absorption
• Resistant organisms (emerging concern with some geographic strains) 3
• Incorrect diagnosis
• Reinfection from untreated contacts or contaminated fomites