Tinea Cruris (Fungal Groin Infection)
Tinea cruris also called jock itch, crotch itch, ringworm of the groin, gym itch or Tinea inguinalis is a disease caused by fungi which live on the skin. It affects the upper thigh, groin, the area of the genitalia and / or the skin of the perineum and around the anus. It appears to be the second most common infection of the skin caused by fungi.
this infection is generally more common in men and is more frequently found in adults that in children. The routes of infection are similar to all other fungal infections caused by dermatophytes (commonly called ringworm infections). They include a direct contact with an infected person / item or a previously infected site on the body (from where, the pathogens have spread to the groin area by using an infected towel or with scratching). Most commonly, the original site of the infection includes feet (also called Tinea pedis).
Ringworm of the groin is more common in hot, humid climates and in people who emigrate from such places. The species most frequently implicated in Tinea cruris include Trichophyton rubrum, Epidermophyton floccosum, Trychophyton interdigitale and Trichophyton verrucosum.
This type of fungal infection can also be sexually transmitted and can cause epidemics in bathing facilities, dormitories or between soldiers. Affected patients may have been wearing tight-fitting garments for longer periods or have been suffering from diabetes or obesity.
It appears as a circular patch, which is easily distinguishable from the surroundings and has a raised, scaly border. Another possible clinical picture involves red, scaly changes with blisters and small bumps. Some species of fungi produce a central clearing of the plaque but others don’t. Jock itch is frequently found on both legs where it extends from the inguinal fold to the inner part of the thigh and backward towards the anus. The skin changes are often itchy, if bacteria join the infection they can even get painful. Commonly, the skin of the scrotum is affected, with some species invading the skin of the buttocks, skin of the lower back or abdomen.
candidosis (occurs more commonly in women and classically does not present with a well demarcated border), pityriasis versicolor, erythrasma, inflammation between skin folds (common in the obese people), psoriasis, mycosis fungoides, atopic eczema, lichen simplex chronicus, contact dermatitis, Hailey–Hailey disease, Darier’s disease.
If topical corticosteroid have been used in the course of the disease, symptoms can be suppressed and the diagnosis difficult to determine.
After a careful examination, the doctor might collect some scales of skin from the margin of the lesion and then examine them under a microscope. Biopsy is rarely performed.
ringworm of the groin is typically treated with topical anti fungal medications (including Terbinafine, topical Clotrimazole and Miconasole). If the patient is unable to apply it regularly or if the infection has spread to a large area, orally taken systemic drugs might be subscribed. It is important for the patient to keep the affected part of the skin dry, clean and to change into dry clothes as soon as possible after getting wet. It is also advisable to put on socks before putting on underwear in order to refrain from spreading the infection.
Sometimes, anti fungal powders are used as a preventive measure. If obese, weight loss is strongly advised.
Prognosis is very good unless the subjected area is not kept dry – if not, recurrence is frequent.
Jock itch prevention
in order to properly treat jocks itch, it is essential to treat the almost always present fungal infection of the feet. In hotter areas, light clothing is preferred. If an infection is taking place, the patient should not share towels or any piece of clothing with others in order to refrain from spreading the pathogens. The underwear should be changed daily and the groin kept clean and dry.