Macroconidia of the dermatophytic fungus Epidermophyton floccosum, a fungus that commonly causes jock itch.
Jock itch, also known as crotch itch, gym itch, eczema marginatum, ringworm of the groin, or tinea cruris, is a fungal infection of the groin caused by dermatophytes (Microsporum, Trichophyton, and Epidermophyton). It is more common in males, and is predisposed by increased moisture (as in hot, humid summer times), which promotes growth of the fungus
Jock itch tends to cause itchy or burning sensation in the groin, thigh skin folds, or the anus; the rash appears as raised red plaques that may blister, ooze, or advance down the inner thigh. As the rash advances, it often forms a central area of clearing with advancing borders resembing a ring (hence the name ringworm). Tinea cruris is diagnosed by scraping some of the affected skin onto a glass slide, applying potassium hydroxide (KOH) to dissolve keratin from the skin cells to release the hyphae, heating the slide, and looking under the microscope for hyphae. A sample may also be sent to a lab for a mycotic culture (where the fungus is grown in Sabouraud’s agar). This article will help you treat and cure this fungal infection.
Keep the skin area dry and clean. This will prevent the fungus from growing. Shower and change underwear daily. Also shower after playing sport, exercising, or sweating excessively. After showering, dry the groin area completely. Apply antifungal or drying powders to keep the area dry, if you are susceptible to jock itch. Baby powder, for example, is helpful.
Do not scratch the affected area, and do not wear clothes that rub and irritate the area. Keeping the area free from irritation will help the skin regenerate faster.
Apply a topical antifungal agent, such as a cream or powder containing tolnaftate, terbinafine, naftifine, econazole nitrate, Oxiconazole, clotrimazole, or miconazole. You can get these over the counter from drug stores, or you can get a prescription from your doctor to be filled at the pharmacy. If they help, be sure to use these medications for the full 2-4 weeks, or as directed, to clear the infection completely. These antifungal drugs belong to the azole class, which works by stopping the fungus from making ergosterol, an essential component of the fungal cell membrane. Without ergosterol, the cell membrane cannot be made, and the fungus will die.