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

Ringworm (Tinea) Treatment

For most ringworm infections of the body (tinea corporis) and groin (tinea cruris), topical antifungal therapy is first-line treatment, with terbinafine 1% cream applied once daily for 1 week being the most effective option. 1

Topical Treatment by Location

Tinea Corporis and Tinea Cruris (Body and Groin)

• Terbinafine 1% cream once daily for 1 week is the preferred first-line treatment with high efficacy 1
• Butenafine twice daily for 2 weeks is an effective over-the-counter alternative for adults 1
• Clotrimazole twice daily for 4 weeks is another proven option, though requires longer treatment duration 1
• Other topical options include azoles, amorolfine, ciclopiroxolamine, and tolnaftate 2

Tinea Pedis (Foot)

• Topical antifungals for 4-8 weeks are typically required 3
• Same agents as above can be used, but treatment duration is longer 4
• Important caveat: If erosion or contact dermatitis is present, topical drugs may cause irritant dermatitis and worsen the condition—in these cases, start with oral antifungals plus topical corticosteroids, then transition to topical antifungals after complications resolve 5

When Oral Therapy is Required

Oral antifungal agents are mandatory for:

• Tinea capitis (scalp) - topical therapy alone is ineffective because the infection involves hair shafts 6, 4
• Tinea unguium/onychomycosis (nails) - topical agents cannot adequately penetrate 4
• Extensive disease involving large body surface areas 4
• Hyperkeratotic tinea pedis unresponsive to topical therapy 5
• Tinea facialis near eyes, ears, or mouth where topical application is difficult 5
• Immunocompromised patients 4
• Lack of response to topical treatment 4

Oral Antifungal Regimens

For Tinea Capitis:

• Oral terbinafine is first-line therapy - well tolerated, effective, and inexpensive, requiring 6 weeks of treatment 6, 4
• Griseofulvin remains the drug of choice for Microsporum-type tinea capitis, requiring 4-6 weeks of treatment at 10 mg/kg daily for children 3, 7, 6
• Adult griseofulvin dosing: 500 mg daily (can be given as 125 mg four times daily, 250 mg twice daily, or 500 mg once daily) 3

For Other Tinea Infections Requiring Oral Therapy:

• Terbinafine is generally preferred for dermatophyte infections 4, 2
• Itraconazole allows for short-duration therapy and is effective for most dermatophytoses 7, 2
• Fluconazole is an alternative option 2

For Tinea Corporis/Cruris: 2-4 weeks of oral therapy when indicated 3

For Onychomycosis: Fingernails require at least 4 months; toenails require at least 6 months 3

Critical Treatment Principles

• Always combine oral antifungal therapy with topical antifungal treatment to optimize outcomes 2
• Confirm diagnosis before treatment with KOH preparation, fungal culture, or nail biopsy 3
• Continue treatment until the organism is completely eradicated, not just until symptoms resolve—clinical relapse will occur if medication is stopped prematurely 3
• Monitor treatment response with follow-up cultures; if clinical improvement occurs but mycology remains positive, continue current therapy for an additional 2-4 weeks 1

Prevention Strategies

• Cover active foot lesions with socks before putting on underwear to prevent autoinoculation to the groin 1
• Completely dry crural folds after bathing to prevent recurrence 1
• Use separate towels for drying the groin versus other body parts 1
• Address general hygiene measures to control sources of infection or reinfection 3

Emerging Resistance Concerns

Trichophyton mentagrophytes ITS genotype VIII (T. indotineae) infections:

• These emerging infections are usually terbinafine-resistant 2
• Require species identification, genotype determination, and resistance testing 2
• Itraconazole is the drug of choice for these resistant infections 2
• May require prolonged oral therapy and do not respond to standard first-line treatments 4

Treatment-refractory onychomycosis:

• May be due to terbinafine resistance in T. rubrum 2
• Consider resistance testing and alternative treatment with itraconazole 2

Common Pitfalls

• Avoid combination antifungal-corticosteroid products as part of antifungal stewardship to prevent resistance 4
• Treatment failure often results from poor compliance, suboptimal medication absorption, or organism insensitivity 1
• Do not use griseofulvin for yeast infections (Candida), bacterial infections, or other non-dermatophyte fungal infections—it is ineffective 3
• In tinea pedis, yeasts and bacteria may coexist with dermatophytes; griseofulvin will not eradicate these co-infections 3