Tinea Corporis, Cruris & Pedis

Definition

Tinea corporis, cruris, and pedis are superficial dermatophyte infections of the skin affecting the body (corporis), groin (cruris), and feet (pedis), caused by fungi of the genera *Trichophyton*, *Microsporum*, and *Epidermophyton*.

Epidemiology

• Common worldwide, especially in warm, humid climates.
• Affects all age groups, more frequent in adults and males (tinea cruris).
• Tinea pedis is common in adolescents and adults, often associated with occlusive footwear.
• Risk factors: sweating, obesity, diabetes, immunosuppression, poor hygiene, communal bathing facilities.
• Higher prevalence in athletes and individuals wearing tight or non-breathable footwear.

Etiology

• Dermatophyte fungi: *Trichophyton rubrum*, *T. mentagrophytes*, *Epidermophyton floccosum*, *Microsporum* species.
• Transmission: direct skin-to-skin contact, contaminated surfaces (floors, towels, shoes).
• Risk factors: occlusive clothing, warm and humid environment, shared facilities, immunosuppression.

Pathophysiology

• Fungi invade the stratum corneum of the epidermis, metabolizing keratin.
• Induces local inflammatory response: erythema, scaling, vesicles, and itching.
• Chronic or recurrent infection may result in hyperkeratosis, fissuring, or secondary bacterial infection.
• Autoinoculation from one site to another can occur.