Treatment for Ringworm (Tinea Infections)
For typical ringworm of the body (tinea corporis) or groin (tinea cruris), topical antifungal therapy with terbinafine or an azole (clotrimazole, miconazole) applied once or twice daily for 2 weeks is the recommended first-line treatment.
Topical Therapy for Localized Infections
First-Line Topical Agents
Topical therapy is appropriate for uncomplicated tinea corporis and tinea cruris that are limited in extent and do not involve hair follicles 1, 2.
- Terbinafine (allylamine) is fungicidal and highly effective, requiring only 1-2 weeks of once-daily application 3, 4, 2
- Azoles (clotrimazole 1%, miconazole 2%) are fungistatic and require 2-4 weeks of treatment 3, 2
- Naftifine (benzylamine) is fungicidal and demonstrates superior efficacy compared to placebo (NNT 3) 4
Treatment Duration by Site
- Tinea corporis and tinea cruris: 2 weeks of treatment 2
- Tinea pedis: 4 weeks with azoles, or 1-2 weeks with allylamines 2
- Continue treatment for at least 1 week after clinical clearing to prevent relapse 2
Comparative Effectiveness
Terbinafine demonstrates significantly higher clinical cure rates compared to placebo (RR 4.51, NNT 3), with low-quality evidence 4. Azoles and allylamines show similar mycological cure rates when compared head-to-head, though substantial heterogeneity exists in the data 4.
Oral Therapy for Extensive or Resistant Infections
Indications for Systemic Treatment
Oral antifungals are indicated when topical therapy fails, disease is extensive, the patient is immunocompromised, or hair follicles are involved (tinea capitis) 1.
First-Line Oral Agent
Terbinafine is considered first-line oral therapy because it is well-tolerated, effective, and inexpensive 1.
Alternative Oral Agents
Griseofulvin is FDA-approved for dermatophyte infections at 500 mg daily in adults (or 10 mg/kg daily in children over 2 years) 5
Fluconazole has better activity against Candida than dermatophytes and is less effective than terbinafine for dermatophyte infections, though it is used for tinea capitis in children at weight-based doses 7
Important Clinical Considerations
Diagnostic Confirmation
Accurate diagnosis with KOH preparation, fungal culture, or nail biopsy should be obtained before initiating treatment, as other conditions (eczema, psoriasis) can mimic tinea infections 5, 1.
Common Pitfalls to Avoid
- Avoid combination antifungal-corticosteroid products as part of antifungal stewardship to prevent resistance 1
- Do not use topical therapy alone for tinea capitis or onychomycosis, as these require systemic treatment due to hair follicle and nail involvement 1, 3
- Fungistatic agents (azoles) require longer treatment duration than fungicidal agents (allylamines), and premature discontinuation leads to higher recurrence rates 3
Emerging Resistant Infections
Emerging tinea infections may be more severe and generally do not improve with first-line topical or oral antifungals, requiring prolonged oral therapy and specialized diagnostic testing 1.
Adverse Effects
All topical antifungal treatments demonstrate minimal adverse effects, primarily limited to local irritation and burning, with no significant difference between active treatments and placebo 4.