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

Treatment of Ringworm (Tinea Infections)

For most ringworm infections of the body (tinea corporis), groin (tinea cruris), and feet (tinea pedis), start with topical antifungal therapy, but scalp ringworm (tinea capitis) and nail infections (tinea unguium) require oral systemic antifungal treatment. 1

Location-Based Treatment Algorithm

Tinea Corporis, Tinea Cruris, and Tinea Pedis (Body, Groin, Feet)

Topical therapy is first-line for uncomplicated infections:

• Apply topical azoles (clotrimazole, miconazole), allylamines (terbinafine), or ciclopiroxolamine to affected areas 2
• Continue treatment for 2-4 weeks for tinea corporis and tinea cruris 3
• Treat tinea pedis for 4-8 weeks 3
• Extend application 2-3 cm beyond visible lesion margins 4

Escalate to oral therapy when:

• Extensive disease covering large body surface areas 4
• Hyperkeratotic tinea pedis unresponsive to topical treatment 5
• Hair follicle involvement 4
• Immunocompromised patients 4
• Lesions near eyes, ears, or mouth where topical application is difficult 5

Tinea Capitis (Scalp Ringworm)

Oral systemic therapy is mandatory—topical treatment alone is inadequate: 1

First-line treatment options based on causative organism:

• For Trichophyton species (most common in many regions):

  • Terbinafine: <20 kg: 62.5 mg daily; 20-40 kg: 125 mg daily; >40 kg: 250 mg daily for 2-4 weeks 1
  • Griseofulvin: 20-25 mg/kg daily for 6-8 weeks (only FDA-approved option for children) 3, 6

• For Microsporum species:

  • Griseofulvin: 20-25 mg/kg daily for 6-8 weeks (preferred for Microsporum) 1
  • Higher doses up to 25 mg/kg may be needed for resistant cases 1

Take griseofulvin with fatty food to enhance absorption 1

Adjunctive measures:

• Add antifungal shampoo (ketoconazole 2%, selenium sulfide 1%, or povidone-iodine) to reduce spore transmission 1
• Screen and treat household contacts for Trichophyton tonsurans infections 1
• Children can attend school during treatment 1

Start treatment immediately if:

• Kerion (severe inflammatory scalp infection) is present 1
• Clinical features strongly suggest tinea capitis (scaling, lymphadenopathy, alopecia) 1
• Do not delay for culture results in high-risk populations, as results take 2-4 weeks 1

Tinea Unguium/Onychomycosis (Nail Infections)

Oral terbinafine is first-line therapy:

• Terbinafine 250 mg daily for fingernails (minimum 4 months) and toenails (minimum 6 months) 3, 4
• Alternative: Itraconazole pulse therapy or fluconazole (off-label) 2
• Always combine oral therapy with topical antifungal application 2

Critical Pitfalls and Special Considerations

Confirm diagnosis before treatment:

• Clinical diagnosis alone is unreliable—tinea corporis mimics eczema, onychomycosis mimics psoriatic nails 4
• Obtain KOH preparation, fungal culture, or nail biopsy before initiating therapy 3

Emerging resistant infections:

• Trichophyton mentagrophytes ITS genotype VIII (T. indotineae) shows terbinafine resistance 2
• If treatment fails, obtain species identification and resistance testing 2
• Switch to itraconazole for terbinafine-resistant infections 2

Treatment failure management:

• First assess compliance, drug absorption, and possibility of reinfection 1
• If clinical improvement but positive mycology persists, continue current therapy 2-4 weeks longer 1
• If no clinical improvement, switch to second-line agent: itraconazole 5 mg/kg daily for 2-4 weeks 1

Monitor for cure:

• Treatment endpoint is mycological clearance, not just clinical improvement 1
• Repeat fungal cultures until negative results confirm eradication 1
• Continue treatment 14 days after clinical resolution to prevent relapse 3

Avoid antifungal-corticosteroid combinations:

• These promote resistance and worsen outcomes through antifungal stewardship principles 4
• For tinea with secondary inflammation, use oral antifungals plus separate topical corticosteroids temporarily, then transition to antifungals alone 5