What is the recommended treatment for tinea corporis?

Treatment of Tinea Corporis

For localized tinea corporis, apply topical terbinafine 1% cream once daily for 1-2 weeks as first-line therapy, reserving oral antifungals for extensive disease, treatment failure, or immunocompromised patients. 1, 2

Diagnostic Confirmation Before Treatment

• Obtain potassium hydroxide (KOH) preparation or fungal culture before initiating therapy to confirm dermatophyte infection and identify the causative organism. 2
• If KOH is negative but clinical suspicion remains high, culture specimens on Sabouraud agar for at least 2 weeks. 3, 2

First-Line Topical Therapy for Localized Disease

Topical antifungals are appropriate for most localized skin infections: 3

• Terbinafine 1% cream once daily for 1-2 weeks is the preferred first-line topical agent. 1, 2
• Alternative topical options include naftifine 1% once daily for 1-2 weeks. 2
• Clotrimazole cream twice daily for 2-4 weeks is another effective option. 1
• Miconazole cream twice daily for 2-4 weeks can also be used. 1
• Ketoconazole 2% cream once daily for 2 weeks is FDA-approved for tinea corporis. 4

Treatment should continue for at least one week after clinical clearing to reduce recurrence risk. 5

Oral Antifungal Therapy Indications

Systemic therapy is indicated when: 1, 3, 2

• The infection is extensive or covers large body surface area 2
• Topical treatment has failed 1, 6
• The patient is immunocompromised 2, 6
• The infection is resistant to topical treatment 1

Oral Antifungal Regimens

Terbinafine is the preferred oral agent for Trichophyton species: 1, 3, 2

• Terbinafine 250 mg daily for 1-2 weeks achieves an 87.1% mycological cure rate and is particularly effective against T. tonsurans. 1, 3, 2
• Baseline liver function tests are recommended before initiating terbinafine, especially with pre-existing hepatic abnormalities. 1, 2

Itraconazole is an effective alternative: 1, 3, 2

• Itraconazole 100 mg daily for 15 days achieves an 87% mycological cure rate. 1, 3, 2
• Itraconazole is particularly useful when the causative organism is unknown or when Microsporum species are suspected. 3
• Important drug interactions exist with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin. 1, 3, 2
• Itraconazole is contraindicated in heart failure. 3, 2

Fluconazole can be considered as a third-line option: 1, 7, 8

• Fluconazole 150 mg once weekly for 2-4 weeks is effective but has limited comparative efficacy data and is less cost-effective than terbinafine. 1, 7, 8

Treatment Monitoring and Endpoints

Mycological cure (negative microscopy and culture) is the definitive treatment endpoint, not just clinical improvement: 1, 3, 2

• Repeat mycology sampling at the end of the standard treatment period and continue monthly until mycological clearance is documented. 1, 3, 2
• If clinical improvement occurs but mycology remains positive, continue current therapy for an additional 2-4 weeks. 3, 2
• If there is no initial clinical improvement, switch to second-line therapy. 3, 2

Prevention of Recurrence

Comprehensive prevention strategies are essential to avoid reinfection: 1, 3, 2

• Screen and treat all household contacts, as over 50% may be affected with anthropophilic species like T. tonsurans. 1, 2
• Clean all fomites (combs, brushes, towels, clothing) with disinfectant or 2% sodium hypochlorite solution. 1, 2
• Avoid skin-to-skin contact with infected individuals and do not share personal items. 1, 2
• Apply antifungal powders (miconazole, clotrimazole, or tolnaftate) to prevent reinfection in high-risk individuals. 3, 2
• Cover lesions during treatment to prevent transmission. 1

Common Pitfalls and Special Considerations

• Do not delay systemic antifungal therapy if extensive disease is present - waiting for culture results is unnecessary when clinical presentation is clear. 3
• Avoid using topical corticosteroid-antifungal combinations as first-line therapy - while they may provide faster symptomatic relief, they should be used with caution due to potential for skin atrophy. 5
• Griseofulvin should not be used as first-line treatment - it requires longer treatment duration, is less effective than terbinafine, and has lower cure rates. 1
• For athletes with tinea corporis, minimum 72 hours of topical or systemic antifungal therapy is required before return to competition, with lesions covered by gas-permeable dressing. 9