Disease name and synonyms

Tinea cruris (Jock itch, genitocrural dermatophytosis)

Fungi responsible

Dermatophytes such as Trichophyton rubrum and Epidermophyton floccosum but Candida albicans can also cause it, if the area is damp (intertrigo)

Disease description

Confluent, red, scaly rash covering the groin, scrotum and upper thighs. The central part of the rash may clear. The penile shaft is not affected. Intense pruritus (itching) is common. Localised scrotal infection is quite common and inconspicuous. There may be evidence of superficial fungal infection elsewhere on the body. A common differential diagnosis is cutaneous candidaiasis, in which satellite lesions are common.

Frequency and global burden

Tinea cruris is more common in men than women, and tends to occur between the ages of 18 and 60. Worldwide in distribution. Highly contagious and mini-outbreaks can occur, in settings where towels are shared, for example.

Underlying problems and at risk patients

None especially, other than sharing of bathing facilities.

Diagnostic testing

Skin scraping with microscopy and fungal culture.

Treatments

Local application of topical antifungal cream twice daily for 2-3 weeks is usually sufficient. If there is evidence of extensive infection then oral therapy with itraconazole or terbinafine is better.

Outlook and prognosis

Excellent, although relapse occurs if other lesions on the body are not treated or treatment is not continued long enough.