What is the management of Tinea corporis?

Management of Tinea Corporis

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

Diagnostic Confirmation

• Obtain potassium hydroxide (KOH) preparation or fungal culture before initiating treatment to confirm dermatophyte infection and identify the causative organism 2
• Look for characteristic annular scaly plaques with central clearing and active raised borders 3
• Culture specimens on Sabouraud agar if KOH is negative but clinical suspicion remains high 4

First-Line Topical Therapy

Topical antifungals are appropriate for localized, limited skin involvement in immunocompetent patients:

• Terbinafine 1% cream applied once daily for 1-2 weeks is the preferred topical agent due to shorter treatment duration compared to azoles 1, 2
• Alternative topical options include naftifine 1% once daily for 1-2 weeks 1
• Azole creams (clotrimazole, miconazole) applied twice daily for 2-4 weeks are effective but require longer treatment duration 3, 5
• Continue treatment for at least one week after clinical clearing to prevent relapse 3

Oral Antifungal Therapy

Systemic therapy is indicated when:

• Infection is extensive or covers large body surface area 1, 2
• Topical therapy has failed 1, 2
• Patient is immunocompromised 1, 2
• Application of topical agents is not feasible 6

Oral Treatment Regimens:

• Terbinafine 250 mg daily for 1-2 weeks achieves 87.1% mycological cure rate and is the preferred oral agent 4, 2
• Itraconazole 100 mg daily for 15 days achieves 87% mycological cure rate, superior to griseofulvin (57% cure rate) 4, 1
• Fluconazole 150 mg once weekly for 2-4 weeks is an alternative option with 79% clinical cure rate 7, 8
• Griseofulvin should not be used as first-line therapy due to longer treatment duration and lower efficacy 2, 9

Treatment Monitoring and Endpoints

• Mycological cure (negative microscopy and culture), not just clinical improvement, is the definitive treatment endpoint 1, 2
• Repeat mycology sampling at the end of standard treatment period and continue monthly until mycological clearance is documented 1
• Clinical response typically occurs within 1-2 weeks, but continue treatment to completion to prevent relapse 3

Prevention of Recurrence

Essential preventive measures include:

• Screen and treat all household contacts, as over 50% may be affected with anthropophilic species like T. tonsurans 2
• Clean all fomites (combs, brushes, towels, clothing) with disinfectant or 2% sodium hypochlorite solution 2
• Avoid skin-to-skin contact with infected individuals and cover lesions during treatment 4
• Do not share towels, clothing, or sports equipment 4
• Apply antifungal powders (miconazole, clotrimazole, tolnaftate) to prevent reinfection in high-risk individuals 1

Special Considerations and Pitfalls

• Avoid topical steroid-antifungal combination creams except for severe inflammation, as they may cause skin atrophy and are not recommended in clinical guidelines despite showing higher short-term clinical cure rates 5
• Baseline liver function tests are recommended before initiating oral terbinafine or itraconazole, especially with pre-existing hepatic abnormalities 1
• Itraconazole is contraindicated in heart failure and has significant drug interactions with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin 1
• Terbinafine is more effective against Trichophyton species, while griseofulvin is more effective against Microsporum species if organism-directed therapy is needed 4, 1
• Topical therapy alone is not adequate for tinea capitis or tinea unguium, which require systemic treatment 4, 9

Treatment Failure Management

If initial therapy fails:

• First assess compliance, drug absorption, and potential reinfection sources 4
• If clinical improvement occurs but mycology remains positive, continue current therapy for an additional 2-4 weeks 4
• If no clinical improvement, switch to alternative oral agent: use itraconazole if terbinafine failed, or terbinafine if azole failed 4, 2