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 Approach
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 for 2-4 weeks 2
- Treat tinea corporis for 2-4 weeks, tinea pedis for 4-8 weeks 3
- Continue treatment for 1-2 weeks after clinical resolution to prevent relapse 4
Switch 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 antifungal therapy is mandatory—topical treatment alone is inadequate: 1
First-line treatment depends on the causative organism:
For Trichophyton species (most common in many regions): Terbinafine is preferred 4
- Weight-based dosing: <20 kg: 62.5 mg/day; 20-40 kg: 125 mg/day; >40 kg: 250 mg/day for 2-4 weeks 1
For Microsporum species: Griseofulvin remains the drug of choice 1, 6
Adjunctive measures:
- Add antifungal shampoo (ketoconazole 2%, selenium sulfide 1%, or povidone-iodine) to reduce spore transmission 1
- Screen and treat family members and close contacts, especially for Trichophyton tonsurans 1
- Children can attend school/nursery while on appropriate treatment 1
When to start treatment:
- Begin immediately if kerion present or diagnosis strongly suspected clinically (scaling, lymphadenopathy, alopecia) without waiting for culture results 1
- Culture results take 2-4 weeks and delaying treatment increases transmission risk 1
Tinea Unguium/Onychomycosis (Nail Infections)
Oral terbinafine is first-line therapy: 4
- Fingernails: 250 mg daily for at least 4 months 3
- Toenails: 250 mg daily for at least 6 months 3
- Terbinafine is well-tolerated, effective, and inexpensive 4
Alternative oral options:
- Itraconazole or fluconazole for terbinafine-resistant cases 2
- Always combine oral therapy with topical antifungals 2
Treatment Failure Management
If no clinical improvement after standard duration:
- Verify compliance and ensure adequate drug absorption 1
- Confirm diagnosis with microscopy (KOH prep) and culture 1, 3
- For tinea capitis with ongoing positive cultures but clinical improvement: Continue current therapy 2-4 weeks longer 1
- For tinea capitis with no clinical improvement: Switch agents 1
- If on terbinafine for Trichophyton → switch to griseofulvin
- If on griseofulvin for Microsporum → switch to terbinafine
- Consider itraconazole 50-100 mg/day or 5 mg/kg/day for 2-4 weeks 1
Emerging Resistant Infections
Suspect Trichophyton mentagrophytes ITS genotype VIII (T. indotineae) if:
- Severe, extensive tinea corporis or cruris not responding to standard treatment 2
- Known terbinafine resistance 2
Management approach:
- Obtain species identification, genotype testing, and resistance testing 2
- Itraconazole is the drug of choice for T. indotineae 2
- Avoid combination antifungal-corticosteroid products to prevent resistance 4
Critical Pitfalls to Avoid
- Never use topical therapy alone for tinea capitis—it will fail and cause treatment delays 1
- Never use topical steroids alone on suspected fungal infections—this worsens infection 4
- Do not stop treatment when symptoms resolve—continue until mycological cure confirmed to prevent relapse 3
- Avoid topical antifungals on eroded/inflamed interdigital tinea pedis—start with oral antifungals plus topical corticosteroids, then add topical antifungals after inflammation resolves 5