What is the treatment for tinea corporis?

Treatment of Tinea Corporis

Topical antifungal therapy is the first-line treatment for localized tinea corporis, with allylamine agents (terbinafine or naftifine) preferred due to their shorter treatment duration of 1-2 weeks compared to azoles. 1

Diagnostic Confirmation Before Treatment

• Always confirm dermatophyte infection via potassium hydroxide (KOH) preparation or fungal culture before initiating therapy. 1
• Specimens should be collected using scalpel scraping from the active border of the lesion. 2
• Accurate diagnosis is essential because tinea corporis has many mimics including eczema, and treatment should not be initiated based on clinical appearance alone. 3

First-Line: Topical Antifungal Therapy

Preferred Agents - Allylamines

• Terbinafine cream or naftifine cream applied for 1-2 weeks is the optimal topical choice. 1, 4
• Allylamines offer superior convenience with shorter treatment duration compared to azoles. 1
• Naftifine 1% achieves mycological cure rates 2.38 times higher than placebo (NNT 3). 5
• Terbinafine achieves clinical cure rates 4.51 times higher than placebo (NNT 3). 5

Alternative Agents - Azoles

• Azole antifungals (clotrimazole, miconazole, ketoconazole) require 2-4 weeks of treatment. 4
• Clotrimazole 1% achieves mycological cure rates 2.87 times higher than placebo (NNT 2). 5
• No significant difference exists in mycological cure rates between azoles and benzylamines. 5

Treatment Duration

• Continue topical therapy for at least one week after clinical clearing of infection. 4
• Standard treatment duration for tinea corporis is 2-4 weeks with azoles or 1-2 weeks with allylamines. 4, 6

Second-Line: Oral Antifungal Therapy

Indications for Systemic Treatment

• Oral antifungals are indicated when infection is extensive, resistant to topical treatment, involves immunocompromised patients, or after topical treatment failure. 1, 3

Preferred Oral Agent - Terbinafine

• Terbinafine 250 mg daily for 1-2 weeks is the first-line oral therapy, particularly effective against Trichophyton tonsurans. 1, 2
• Achieves mycological cure rate of 87.1% at 6-week follow-up. 1
• Well tolerated with gastrointestinal disturbances (49%) being the most common side effect. 1
• Serious adverse events are rare (0.04% incidence). 1
• Contraindicated in patients with active or chronic liver disease and lupus erythematosus. 1
• Has minimal drug-drug interactions compared to azoles. 1

Alternative Oral Agent - Itraconazole

• Itraconazole 100 mg daily for 15 days achieves 87% mycological cure rate, superior to griseofulvin's 57%. 1, 2
• Licensed for children over 12 years in the UK. 2
• Important drug interactions include enhanced toxicity with warfarin, certain antihistamines, antipsychotics, midazolam, digoxin, and simvastatin. 2

Griseofulvin - Not Recommended First-Line

• Griseofulvin should not be used as first-line treatment due to longer treatment duration (2-4 weeks), lower effectiveness than terbinafine, and inferior cure rates. 2, 7
• Dosing: Adults 0.5 g daily; pediatric patients >2 years at 10 mg/kg daily. 7

Critical Treatment Monitoring

• Mycological cure, not just clinical response, is the definitive treatment endpoint. 1, 2
• Follow-up with repeat mycology sampling is recommended until mycological clearance is documented. 1, 2
• If clinical improvement occurs but mycology remains positive, continue therapy for an additional 2-4 weeks. 1

Prevention of Recurrence

• Screen and treat all family members, as over 50% of household contacts may be affected with anthropophilic species like T. tonsurans. 1, 2
• Clean all fomites (combs, brushes, towels) with disinfectant or 2% sodium hypochlorite solution. 1, 2
• Avoid skin-to-skin contact with infected individuals and do not share towels or personal items. 1, 2

Common Pitfalls to Avoid

• Do not use combination antifungal/steroid agents routinely - while they may provide faster clinical improvement, they should be used with caution due to potential for skin atrophy and steroid-associated complications. 4
• Do not rely solely on clinical appearance for diagnosis, as many conditions mimic tinea corporis. 3, 8
• Do not discontinue treatment based on clinical clearing alone without mycological confirmation of cure. 1