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

Treatment for Ringworm (Tinea Infection)

For ringworm infections, oral antifungal therapy is generally indicated to achieve both clinical and mycological cure, with the choice of medication depending on the causative dermatophyte and infection location. 1

First-Line Treatment Options

For Tinea Capitis (Scalp Ringworm)

Treatment should be directed by the causative dermatophyte:

1. For Trichophyton species infections:

   • Terbinafine (oral) is the preferred treatment 1
   • Dosing by weight:
     • <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

2. For Microsporum species infections:

   • Griseofulvin is more effective 1
   • Dosing by weight:
     • <50 kg: 15-20 mg/kg/day for 6-8 weeks

     • 50 kg: 1 g/day for 6-8 weeks

For Tinea Corporis/Cruris (Body/Groin Ringworm)

• Topical antifungals are generally effective for localized infections 2
  • Terbinafine 1% cream applied twice daily for 1-2 weeks shows superior efficacy compared to longer courses of clotrimazole 3
  • Azole creams (clotrimazole, miconazole) applied twice daily for 2-4 weeks

Second-Line Treatment Options

If first-line therapy fails:

• Itraconazole:

  • Adults: 100 mg daily for 2-4 weeks
  • Children: 5 mg/kg/day for 2-4 weeks 1

• Fluconazole: Can be considered for refractory cases 1

Treatment Algorithm

1. Identify the location and extent of infection:

   • Scalp involvement (tinea capitis) → Requires oral therapy
   • Body/groin (tinea corporis/cruris) → Topical therapy for limited disease, oral for extensive disease

2. For tinea capitis:

   • If possible, identify causative organism through laboratory testing
   • For Trichophyton species → Terbinafine (shorter course)
   • For Microsporum species → Griseofulvin (longer course)

3. For tinea corporis/cruris:

   • Limited disease → Topical terbinafine or azole cream
   • Extensive or resistant disease → Consider oral therapy as for tinea capitis

Important Clinical Considerations

• Laboratory diagnosis: When possible, obtain samples for KOH preparation and culture before starting treatment 1

• Treatment duration: Continue treatment until clinical and mycological cure is achieved 1

• Monitoring: For oral therapy, consider monitoring liver function, especially with terbinafine 4

• Common pitfalls:

  • Inadequate treatment duration leading to recurrence
  • Failure to identify and treat asymptomatic carriers in household contacts 1
  • Not addressing predisposing factors (excessive moisture, occlusive clothing)

• Side effects to watch for:

  • Terbinafine: Gastrointestinal disturbances, taste disturbance, liver enzyme elevations 4
  • Griseofulvin: Gastrointestinal effects, headache, photosensitivity 1

Special Populations

• Children: Both terbinafine and griseofulvin are effective in children with tinea capitis 5
• Immunocompromised: May require longer treatment courses and closer monitoring

Remember that the endpoint of treatment is mycological rather than just clinical cure, so continue treatment until the infection is completely eradicated 1.