1. Etiology & Dermatophyte Pathophysiology
Tinea Corporis is a superficial dermatophyte fungal infection of the glabrous skin, predominantly caused by Trichophyton rubrum, Trichophyton mentagrophytes, or Microsporum canis. These fungi produce keratinases that digest keratin in the stratum corneum, creating characteristic centrifugal spreading rings with central clearing.
2. Diagnostic Procedures & KOH Mount
Direct microscopic examination of edge skin scrapings dissolved in 10–20% potassium hydroxide (KOH) reveals branching, septate hyphae with arthroconidia, confirming dermatophyte infection and excluding annular psoriasis or erythema annulare centrifugum.
3. Antifungal Regimens
Localized infections respond to topical allylamines (Terbinafine 1% cream daily for 1–2 weeks) or azoles (Clotrimazole 1%). Extensive or recurrent infections warrant oral Terbinafine (250mg daily for 2–4 weeks) or Itraconazole.