What is the treatment for Impetigo circinata (ringworm)?

Treatment of Impetigo Circinata (Ringworm)

For impetigo circinata (ringworm/tinea corporis), apply topical terbinafine or other antifungal cream twice daily for 2-4 weeks, as this is a dermatophyte infection requiring antifungal—not antibacterial—therapy. 1, 2

Critical Distinction: This is NOT Bacterial Impetigo

The term "impetigo circinata" is an older designation for ringworm (tinea corporis), a superficial fungal infection caused by dermatophytes, not the bacterial impetigo caused by Staphylococcus aureus or Streptococcus pyogenes. 3 This distinction is essential because:

• Bacterial impetigo presents with honey-colored crusts, bullae, or weeping lesions and requires antibacterial therapy 4, 5
• Ringworm (tinea corporis) presents with circular, scaly, erythematous patches with raised borders and central clearing, requiring antifungal therapy 1, 3

First-Line Treatment: Topical Antifungals

For localized tinea corporis, topical antifungal therapy is the standard approach:

• Terbinafine cream applied to affected areas twice daily is highly effective for ringworm 1
• Alternative topical agents include clotrimazole, miconazole, or ketoconazole applied twice daily 3
• Treatment duration: Continue for 2-4 weeks, typically extending 1-2 weeks beyond clinical resolution to prevent relapse 2

Second-Line Treatment: Oral Antifungals

Oral antifungal therapy is indicated when:

• Lesions are extensive or involve multiple body sites 2
• Topical therapy has failed after 2-4 weeks 2
• The infection involves hair-bearing areas (tinea capitis) 2
• Immunocompromised patients require more aggressive treatment 3

Oral treatment options:

• Griseofulvin: 500 mg daily (or 10 mg/kg/day in children over 2 years), continued for 2-4 weeks for tinea corporis 2
• Terbinafine oral: Alternative systemic option for dermatophyte infections 1

Common Pitfalls to Avoid

• Do not use antibacterial antibiotics (mupirocin, cephalexin, clindamycin) for ringworm—these treat bacterial impetigo, not fungal infections 4, 1
• Do not stop treatment when lesions appear to clear—continue for the full 2-4 week course to eradicate the dermatophyte and prevent recurrence 2
• Confirm the diagnosis with KOH preparation or fungal culture if the presentation is atypical or fails to respond to antifungal therapy 2

Treatment Algorithm

1. Confirm diagnosis: Look for circular lesions with raised, scaly borders and central clearing (not honey-colored crusts) 1, 3
2. Limited disease (few small lesions): Start topical terbinafine or clotrimazole twice daily for 2-4 weeks 1, 3
3. Extensive disease or treatment failure: Switch to oral griseofulvin 500 mg daily for 2-4 weeks 2
4. Reassess at 2 weeks: If no improvement, obtain fungal culture and consider alternative diagnosis 2

Special Considerations

• HIV-positive or immunocompromised patients may require longer treatment courses and closer monitoring, as demonstrated in case reports of extensive tinea in HIV-positive individuals 3
• Concomitant hygiene measures are essential to prevent reinfection and spread to others 2