Tinea Cruris

Tinea cruris is a common dermatophytosis of the groin, genitalia, pubic area, perineal, and perianal skin. The designation is a misnomer, because in Latin “cruris” means of the leg. It is the second-most common dermatophytosis worldwide.

EPIDEMIOLOGY

Much like tinea corporis, tinea cruris spreads via direct contact or fomites, and is exacerbated by occlusion and warm, moist climates. It is three times more common in men than in women, and adults are affected more commonly than children. Again, autoinfection from distant reservoirs such as tinea pedis caused by T. rubrum or T. mentagrophytes is common.

Differential Diagnosis of Tinea Corporis

Most Likely

·         Erythema annulare centrifugum, nummular eczema, granuloma annulare

Consider

·         Psoriasis, lichen planus, seborrheic dermatitis, pityriasis rosea, pityriasis rubra pilaris, polymorphous light eruption, contact dermatitis, acne rosacea

Rule Out

·         Mycosis fungoides, secondary syphilis, lupus erythematosus, dermatomyositis, candidal or deep fungal infections, mycobacterial infections or blastomycosis

ETIOLOGY

Most tinea cruris is caused by T. rubrum and Epidermophyton floccosum, with the latter being most often responsible for epidemics. T. mentagrophytes and T. verrucosum are also less commonly involved.

CLINICAL FINDINGS

Tinea cruris usually appears as multiple erythematous papulovesicles with a well-marginated, raised border. Pruritus is common, as is pain with maceration or secondary infection. E. floccosum tinea cruris is more likely to display central clearing, and is most often limited to the genitocrural crease and the medial upper thigh. In contrast, T. rubrum infections are often coalescent with extension to the pubic, perianal, buttock, and lower abdominal areas . The genitalia are typically unaffected.