What is the treatment for Tinea corporis with lesions on the trunk, legs, back, and arms?

Treatment of Tinea Corporis with Widespread Lesions

For tinea corporis with widespread lesions on the trunk, legs, back, and arms, a minimum of 72 hours of topical antifungal therapy or systemic antifungal therapy is recommended as first-line treatment. 1

First-Line Treatment Options

Topical Therapy

• For limited lesions or mild cases:
  • Terbinafine cream 1% applied once or twice daily for 1-2 weeks
  • Naftifine cream/gel applied once or twice daily for 2 weeks
  • Other azole antifungals (clotrimazole, miconazole, econazole) applied twice daily for 2-4 weeks

Systemic Therapy

• For extensive, widespread lesions affecting multiple body areas:

1. Terbinafine (preferred for Trichophyton species) 2

   • Adults and children >40kg: 250mg daily for 2-4 weeks
   • Children 20-40kg: 125mg daily for 2-4 weeks
   • Children <20kg: 62.5mg daily for 2-4 weeks

2. Itraconazole (alternative, effective against both Trichophyton and Microsporum) 2

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

3. Fluconazole (alternative) 3, 4, 5

   • 150mg once weekly for 2-4 weeks OR
   • 50-100mg daily for 2-3 weeks

4. Griseofulvin (particularly for Microsporum infections) 6

   • Adults: 500mg daily (can range from 500mg-1g based on severity)
   • Children: 10mg/kg/day in divided doses
   • Duration: 2-4 weeks for tinea corporis

Treatment Algorithm

1. Assess extent of infection:

   • If lesions are limited to a small area: Use topical therapy
   • If lesions are widespread (multiple body areas as described): Use systemic therapy

2. Consider causative organism:

   • If Trichophyton species suspected/confirmed: Terbinafine preferred
   • If Microsporum species suspected/confirmed: Griseofulvin preferred
   • If unknown: Terbinafine or itraconazole are good empiric choices

3. Monitor response:

   • Clinical improvement should be seen within 1-2 weeks
   • Continue treatment for at least 1 week after clinical clearing of infection 7
   • If no improvement after 2 weeks, consider:
     • Confirming diagnosis (KOH preparation or culture)
     • Switching to alternative antifungal agent

Special Considerations

• Diagnosis confirmation: Prior to initiating treatment, especially systemic therapy, confirm diagnosis with KOH preparation or fungal culture 6

• Adjunctive measures:

  • Avoid excessive washing with hot water 1
  • Use alcohol-free moisturizers twice daily 1
  • Avoid sharing personal items (towels, clothing)
  • Treat all family members if anthropophilic infection is suspected 2

• Treatment failure considerations:

  • Poor compliance
  • Misdiagnosis
  • Resistant organism
  • Underlying immunosuppression

Monitoring and Follow-up

• Continue treatment until complete clinical resolution

• For systemic therapy, monitor for potential side effects:

  • Terbinafine: Gastrointestinal effects, headache, taste disturbance
  • Itraconazole: Gastrointestinal effects, hepatotoxicity
  • Fluconazole: Gastrointestinal effects, headache
  • Griseofulvin: Headache, gastrointestinal effects, photosensitivity

• Consider follow-up mycological examination in resistant or recurrent cases

The choice of oral antifungal should be based on the extent of infection, suspected pathogen, patient factors, and medication availability. For widespread tinea corporis affecting multiple body areas as described, systemic therapy is typically more effective than topical treatment alone.