Tinea Types: Common Dermatophyte Infections Case 2 Moccasin-Variety Tinea Pedis

February 1, 2004
Joe Monroe, PA-C
Joe Monroe, PA-C

A 70-year-old man first noticed thisskin condition when he returned fromthe South Pacific at the end of WorldWar II. Over the years, the rash hasitched only occasionally; however,during a recent spate of hot weather,the eruption became highly pruritic.Applications of an over-the-counter1% hydrocortisone ointment exacerbatedthe condition

A 70-year-old man first noticed thisskin condition when he returned fromthe South Pacific at the end of WorldWar II. Over the years, the rash hasitched only occasionally; however,during a recent spate of hot weather,the eruption became highly pruritic.Applications of an over-the-counter1% hydrocortisone ointment exacerbatedthe condition.On examination, a florid, papulosquamous,dry eruption with welldefinedborders was evident aroundthe rims of both feet. No interdigitalinvolvement was noted. A potassiumhydroxide preparation of scrapings from a lesion's borderwas markedly positive for fungal elements. Moccasin-varietytinea pedis was diagnosed.The duration and nature of the condition made acure unlikely; thus, the goal of treatment was disease control.Oral terbinafine, 250 mg/d for 1 week, and twice-dailyapplication of terbinafine cream were prescribed. The patientwas told to avoid corticosteroids, which exacerbatedermatophyte infections.Moccasin-variety tinea pedis is usually caused byTrichophyton rubrum. This infection tends to be chronic,looks like dry skin, and often does not bother the patient.Careful examination reveals the well-defined, scaly border.In addition, the sole of the affected foot often has a powderydry look with a fine scale that appears to accentuatethe skin lines. Onychomycosis is often a concomitant condition.The differential diagnosis for moccasin-variety tineapedis includes contact dermatitis; eczema; chronic irritation,as from ill-fitting shoes; and psoriasis.