What is the treatment for tinea corporis (ringworm of the skin)?

Treatment of Tinea Corporis

For tinea corporis, topical antifungal therapy is first-line treatment for localized infections, while oral antifungals are reserved for extensive disease, treatment failure, or immunocompromised patients. 1

Topical Antifungal Therapy (First-Line)

Topical antifungals should be applied for 2-4 weeks for tinea corporis. 2, 3

Specific Topical Agents:

• Terbinafine cream is highly effective and requires only 1-2 weeks of treatment, making it more convenient than azoles 4, 3
• Azole antifungals (clotrimazole, miconazole, ketoconazole) applied twice daily for 2-4 weeks are effective alternatives 4, 3
• Naftifine 1% demonstrates superior efficacy compared to placebo with mycological cure rates of 2.38 times higher 4
• Treatment must continue for at least one week after clinical clearing to prevent relapse 3

Important Caveat:

• Avoid combination antifungal-corticosteroid products as routine therapy, as they may promote resistance and cause steroid-related complications including skin atrophy 5, 3
• Combination products may only be considered when significant inflammation is present, but should be used with extreme caution 3

Oral Antifungal Therapy (Second-Line)

Oral therapy is indicated when topical treatment fails, infection is extensive, or the patient is immunocompromised. 1

Specific Oral Regimens:

Terbinafine:

• 250 mg daily for 1-2 weeks is particularly effective against Trichophyton tonsurans 1, 6
• Considered first-line oral therapy due to excellent tolerability, efficacy, and low cost 5

Itraconazole:

• 100 mg daily for 15 days achieves 87% mycological cure rate 1
• Alternative dosing: 200 mg daily for 7 days 6
• Superior to griseofulvin (87% vs 57% cure rate) 1
• Important drug interactions: Enhanced toxicity with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin 1

Fluconazole:

• 150 mg once weekly for 2-4 weeks is effective 6, 7
• Alternative: 50-100 mg daily for 2-3 weeks 6
• Consider as third-line option due to limited comparative efficacy data and cost-effectiveness concerns 1

Griseofulvin:

• NOT recommended as first-line due to longer treatment duration (2-4 weeks), lower efficacy than terbinafine, and inferior cure rates 1, 2
• Dosing if used: 0.5 g daily (500 mg/day) for adults, 10 mg/kg/day for children over 2 years 2

Treatment Monitoring and Endpoints

The definitive treatment endpoint is mycological cure, not just clinical improvement. 1

• Confirm diagnosis with potassium hydroxide preparation or culture before initiating treatment 1, 2
• Follow-up should include repeat mycology sampling until clearance is documented 1
• Never stop treatment based on clinical appearance alone - mycological confirmation of cure is mandatory 1

Prevention of Recurrence

Essential measures to prevent reinfection include: 1

• Avoid skin-to-skin contact with infected individuals
• Do not share towels, clothing, or personal items
• Cover lesions during treatment
• Clean contaminated combs, brushes, and fomites with disinfectant or 2% sodium hypochlorite solution
• Screen and treat all family members if infection is caused by anthropophilic species like T. tonsurans, as over 50% may be affected 1

Critical Pitfalls to Avoid

• Do not use topical therapy alone for extensive infections - this leads to treatment failure 1
• Do not stop treatment when lesions clear clinically - continue until mycological cure is confirmed 1, 3
• Do not routinely prescribe antifungal-steroid combinations - this promotes resistance and causes complications 5
• Do not forget to assess household contacts for infection, especially with anthropophilic organisms 1
• If treatment fails, assess for non-compliance, suboptimal absorption, organism resistance, or reinfection before switching agents 1