Treatment of Ringworm (Tinea Corporis)
For ringworm (tinea corporis), topical antifungal therapy is the first-line treatment, with topical terbinafine 1% cream applied once or twice daily for 1-2 weeks being the most effective option based on its fungicidal properties and superior cure rates.
Topical Therapy (First-Line)
Preferred Agent: Terbinafine (Allylamine)
- Terbinafine 1% cream applied twice daily for 1 week achieves mycological cure rates of 93.5% and effective treatment rates of 89.7% 1
- Terbinafine is fungicidal (kills fungi) rather than fungistatic, allowing for shorter treatment duration and lower relapse rates 2
- Treatment duration: 1-2 weeks for tinea corporis 3, 4
- Continue treatment for at least one week after clinical clearing of infection 3
Alternative Topical Agents
- Naftifine 1% cream (another allylamine): Achieves 2.38 times higher mycological cure compared to placebo (NNT 3) 4
- Azoles (clotrimazole, miconazole, ketoconazole): Require longer treatment duration (2-4 weeks) as they are fungistatic rather than fungicidal 3, 2
Important Considerations for Topical Therapy
- Diagnosis must be confirmed by KOH preparation, fungal culture, or clinical appearance before initiating treatment 5, 3
- Topical therapy is generally successful unless infection covers an extensive area or is resistant to initial therapy 3
- Azoles and steroid combination creams show higher clinical cure rates at end of treatment but are not recommended in clinical guidelines due to potential steroid-related complications including skin atrophy 3, 4
Systemic Therapy (Second-Line)
When to Use Systemic Treatment
Systemic antifungal therapy is indicated when 5, 3:
- Infection covers an extensive area
- Topical therapy fails or infection is resistant
- Hair follicle involvement is present
- Patient cannot adequately apply topical therapy
Systemic Agent: Griseofulvin
- Adults: 500 mg daily (can be given as 125 mg four times daily, 250 mg twice daily, or 500 mg once daily) 5
- Severe/extensive infections may require 750 mg to 1 g daily initially, then reduced to 500 mg after response 5
- Children >2 years: 10 mg/kg daily in divided doses 5
- 30-50 lbs: 125-250 mg daily
50 lbs: 250-500 mg daily
- Treatment duration for tinea corporis: 2-4 weeks 5
- Medication must be continued until the organism is completely eradicated to prevent clinical relapse 5
Critical Pitfalls to Avoid
- Do not use topical antifungals for nail infections (tinea unguium) - they penetrate poorly through the nail plate and require systemic therapy 2
- Do not use griseofulvin for Candida infections - it is ineffective against yeasts and bacteria 5
- Do not stop treatment when skin appears healed - this leads to higher recurrence rates, especially with fungistatic agents 2
- Address exacerbating factors such as skin moisture and sources of reinfection through hygiene measures 5, 3
- Concomitant topical therapy may be needed alongside systemic treatment 5