What is the treatment for ringworm infections?

Treatment of Ringworm (Tinea) Infections

For localized tinea corporis (body) or tinea cruris (groin), use topical antifungal therapy for 2 weeks; for tinea pedis (feet), treat for 4 weeks; and for tinea capitis (scalp) or extensive/resistant infections, oral antifungal therapy is required. 1, 2

Topical Therapy for Localized Infections

Topical antifungals are first-line treatment for tinea corporis, tinea cruris, and tinea pedis when the infection is limited and not involving hair follicles. 1, 2

Specific Topical Agents and Duration

• Terbinafine cream is highly effective, with significantly higher clinical cure rates compared to placebo (4.51 times more likely to achieve cure), requiring treatment for only 1-2 weeks for tinea corporis/cruris 3, 2
• Naftifine 1% demonstrates strong efficacy with 2.38 times higher mycological cure rates than placebo, applied once or twice daily 3
• Clotrimazole 1% shows 2.87 times higher mycological cure rates compared to placebo, applied twice daily 3
• Azole antifungals (miconazole, econazole, ketoconazole) are effective alternatives, typically applied twice daily for 2 weeks (tinea corporis/cruris) or 4 weeks (tinea pedis) 3, 2

Treatment Duration by Site

• Tinea corporis and tinea cruris: 2 weeks of topical therapy 2
• Tinea pedis: 4 weeks with azoles or 1-2 weeks with allylamines (terbinafine, naftifine) 2
• Continue treatment for at least 1 week after clinical clearing to prevent relapse 2

Oral Antifungal Therapy

Oral antifungals are mandatory for tinea capitis, tinea unguium (onychomycosis), and indicated for extensive disease, immunocompromised patients, lack of response to topical treatment, or hair follicle involvement. 1, 4

Oral Terbinafine (First-Line for Most Indications)

Oral terbinafine is considered first-line therapy for tinea capitis and onychomycosis because it is well-tolerated, effective, and inexpensive. 1

• Tinea capitis: Terbinafine is the preferred agent 1
• Tinea unguium (onychomycosis): Fingernails require at least 4 months; toenails require at least 6 months 5
• Extensive tinea corporis/cruris/pedis: Use when topical therapy fails or disease is widespread 1, 4

Oral Griseofulvin (Alternative for Tinea Capitis)

According to FDA labeling, griseofulvin dosing is 5:

• Adults: 500 mg daily (can give as 125 mg four times daily, 250 mg twice daily, or 500 mg once daily) 5
• Pediatric patients (>2 years): 10 mg/kg daily (30-50 lbs: 125-250 mg daily; >50 lbs: 250-500 mg daily) 5
• Duration: Tinea capitis 4-6 weeks; tinea corporis 2-4 weeks; tinea pedis 4-8 weeks; fingernails at least 4 months; toenails at least 6 months 5
• Must continue until organism is completely eradicated as confirmed by clinical or laboratory examination 5

Other Oral Azoles

• Fluconazole and itraconazole are effective for a range of superficial and invasive fungal infections, though not specifically first-line for dermatophyte infections 6

Special Clinical Situations

Hyperkeratotic Tinea Pedis

Combination of topical and oral antifungal drugs is effective when topical monotherapy fails. 4

Tinea Facialis Near Eyes, Ears, or Mouth

Oral antifungal drugs are necessary when it is difficult to apply topical drugs to all lesions. 4

Tinea Capitis

Oral antifungal drug monotherapy is preferable because topical drugs cause irritation that enhances inflammation. 4

Interdigital Tinea Pedis with Erosion or Contact Dermatitis

Begin treatment with topical corticosteroid therapy combined with oral antifungal drugs active against dermatophytes; use topical antifungals only after complications resolve. 4

Combination Antifungal-Corticosteroid Products

Azole-steroid combination creams show higher clinical cure rates at end of treatment (1.5 times more effective) but similar mycological cure rates compared to azoles alone. 3

• These are not currently recommended in clinical guidelines despite some efficacy data 3
• Antifungal stewardship emphasizes avoiding combination antifungal-corticosteroids to optimize outcomes and prevent resistance 1
• Use with caution due to potential for skin atrophy and other steroid-associated complications 2

Emerging Resistant Tinea Infections

Emerging tinea infections may be more severe than classic infections and generally do not improve with first-line topical or oral antifungals, requiring prolonged oral therapy and specialized diagnostic testing. 1

Diagnostic Confirmation

Accurate diagnosis is essential before initiating treatment; obtain KOH preparation, fungal culture, or nail biopsy to confirm dermatophyte infection. 5, 1, 2

• Clinical diagnosis alone is unreliable as tinea corporis can mimic eczema, and onychomycosis can resemble dystrophic toenails from trauma or psoriasis 1
• Direct microscopy of potassium hydroxide preparation is the primary diagnostic method 2

Common Pitfalls to Avoid

• Do not use griseofulvin for Candida infections, bacterial infections, or other non-dermatophyte fungal infections - it is ineffective 5
• Ensure concomitant use of appropriate topical agents particularly in tinea pedis, as yeasts and bacteria may be involved alongside dermatophytes 5
• Maintain general hygiene measures to control sources of infection or reinfection 5
• Clinical relapse will occur if medication is not continued until the infecting organism is eradicated 5

Adverse Effects

All examined treatments appeared effective with minimal adverse effects, mainly irritation and burning, reported infrequently and generally mild. 3