Tinea cruris (TC), also known as jock itch, is a common type of contagious, superficial fungal infection of the groin and buttocks region, which occurs predominantly but not exclusively in men and in hot-humid climates.
Typically, over the upper inner thighs, there is an intensely itchy red raised rash with a scaly well-defined curved border. "dhobi itch", "crotch itch", "scrot rot", "gym itch", "ringworm of groin" and "eczema marginatum".
Signs and symptoms
Typically, over the upper inner thighs, there is a red raised rash with a scaly well-defined border. There may be some blistering and weeping, and the rash can reach near to the anus.
If the person is hairy, hair follicles can become inflamed resulting in some bumps (papules, nodules and pustules) within the plaque. The plaque may reach the scrotum in men and the labia majora and mons pubis in women. The penis is usually unaffected unless there is immunodeficiency or there has been use of steroids. Rubbing from clothing, excessive sweating, diabetes and obesity are risk factors.
Prevention
To prevent recurrences of tinea cruris, concurrent fungal infections such as athlete's foot need to be treated. Also advised are measures to avoid moisture build-up including keeping the groin region dry, avoiding tight clothing, and losing weight if obese. People with athlete's foot or tinea cruris can prevent spread by not lending their towels to others. There might be a greater cure rate but no guidelines currently recommend its addition.
Prognosis
Tinea cruris is not life-threatening and treatment is effective, particularly if the symptoms have not been present for long.