About Tinea Cruris

Tinea cruris, less glamorously known as “jock itch, is a dermatophytic infection of the groin. Patients also commonly have tinea pedis (athlete’s foot). Moisture from perspiration is likely the predisposing risk factor for both of these rashes.

Tinea cruris may not be annular, but it will be seripiginous, elevated, and scaling. The scrotum is usually uninvolved.

With what can tinea cruris confused?

Candidiasis in the groin area is bright red with ill-defined margins and satellite lesions. Unlike dermatophytic infections, the scrotum is usually involved. Intertrigo is another possible diagnosis that can be confused with tinea cruris, but in intertrigo, the KOH preparation, or fungal culture, will be negative. Tinea cruris can occasionally be confused with psoriasis and seborrheic dermatitis, which can both effect the groin. Erythrasma, caused by Corynebacterium minutissimum, also effect the groin. It fluoresces coral pink under Wood’s lamp exam.

How is tinea cruris (jock itch) treated?

Most cases of tinea cruris can be treated with antifungal creams, such as ketoconazole. For more severe cases, oral antifungals, such as terbinafine (Lamisil) may be required. People that get tinea cruris are prone to recurrence. It is important to keep the area dry. Daily application of moisture absorbing powder, such as talcum powder, or antifungal powder, such as miconazole powder, is advised.

See: Tinea Diagnosis, Treatment and Prognosis