What is the treatment for tinea (ringworm) rash?

Treatment of Tinea (Ringworm) Rash

For tinea (ringworm) rash, oral antifungal therapy is generally required for tinea capitis, while topical antifungal agents are effective for most cases of tinea corporis and tinea cruris. 1

Diagnosis

Before initiating treatment, confirm diagnosis through:

• Direct microscopic examination of skin scrapings with potassium hydroxide
• Culture on appropriate medium when necessary
• Clinical appearance (scaling, erythema, characteristic annular "ring" shape)

Treatment Algorithm by Type

Tinea Capitis (Scalp Ringworm)

Oral therapy is required as topical agents alone are ineffective 1:

1. First-line therapy (based on causative organism):

   • Trichophyton species: Terbinafine orally
     • <20 kg: 62.5 mg daily for 2-4 weeks
     • 20-40 kg: 125 mg daily for 2-4 weeks

     • 40 kg: 250 mg daily for 2-4 weeks

   • Microsporum species: Griseofulvin orally
     • <50 kg: 15-20 mg/kg/day for 6-8 weeks

     • 50 kg: 1 g/day for 6-8 weeks 1, 2

2. Second-line therapy:

   • Itraconazole: 50-100 mg daily or 5 mg/kg/day for 2-4 weeks 1

3. Alternative agents (for refractory cases):

   • Fluconazole (particularly effective for T. violaceum, T. verrucosum, and M. canis) 1

4. Adjunctive therapy:

   • Antifungal shampoo (selenium sulfide 1%, ketoconazole 2%, or povidone-iodine) to reduce spore shedding 1

Tinea Corporis/Cruris (Body/Groin Ringworm)

1. First-line therapy: Topical antifungal agents 3, 4

   • Azoles (clotrimazole, miconazole) applied twice daily for 2-4 weeks
   • Allylamines (terbinafine, naftifine) applied once or twice daily for 1-2 weeks
   • Continue treatment for at least one week after clinical clearing 3

2. For extensive or resistant infections: Oral therapy

   • Terbinafine: 250 mg daily for 1-2 weeks
   • Fluconazole: 150 mg once weekly for 2-3 weeks
   • Itraconazole: 100 mg daily for 2 weeks or 200 mg daily for 7 days 5

Treatment Considerations

Factors Affecting Treatment Choice

• Extent of infection: Widespread lesions may require oral therapy
• Location: Scalp infections always require oral therapy
• Causative organism: Terbinafine is more effective for Trichophyton; griseofulvin for Microsporum 1
• Treatment failure: Consider compliance issues, suboptimal absorption, organism insensitivity, or reinfection 1

Monitoring and Follow-up

• The endpoint of treatment is mycological rather than clinical cure
• Repeat mycology sampling until clearance is achieved for tinea capitis 1
• For tinea corporis/cruris, treatment should continue for at least one week after clinical clearing 3

Common Pitfalls

1. Inadequate treatment duration: Treatment must continue until the infecting organism is completely eradicated 2

2. Failure to address reinfection sources: Implement general hygiene measures to control sources of infection or reinfection 2

3. Misdiagnosis: Accurate diagnosis of the infecting organism is essential before starting treatment 2

4. Stopping treatment too early: Clinical improvement may occur before mycological cure 1

5. Overlooking family members/contacts: For T. tonsurans infections, screen and treat family members and close contacts 1

For most tinea infections, topical therapy is generally successful unless the infection covers an extensive area or is resistant to initial therapy. In these cases, systemic therapy may be required, with the choice of agent guided by the specific dermatophyte involved and local epidemiological patterns.