Erythrasma is a bacterial skin infection which favors moist folds of the skin. The medical term for the folds of the skin found around armpits, the groin, and knees is intertriginous skin, which can be useful to know if you feel like your doctor is speaking in tongues. The infection takes the form of reddish brown raised patches which sometimes itch. If left untreated, the patches will turn brown and scaly, and they have a potential to spread. Although erythrasma looks unsightly, it is relatively easy to treat and is not associated with more serious conditions.

If erythrasma is diagnosed, the patient will be directed to wash the area thoroughly with antibacterial soap on a regular basis. In addition, a topical antibiotic may be prescribed, depending on how serious the condition is. Erythrasma tends to occur more often in people who are overweight, especially diabetics, as they have ample folds of skin which may not always be thoroughly washed. It is also more frequent in hot climates, which can make intertriginous skin more moist and amenable to bacterial colonization.

There are several conditions which can look similar to erythrasma. It is sometimes confused with impetigo, another bacterial infection of the skin. Impetigo appears most often on the hands and face, however, not in the folds of the skin. Infection with tinea, a type of fungus, is also sometimes mistaken for erythrasma, especially since tinea favors the folds of the skin as well. Because all of these conditions require very different treatment, it is important to get a proper diagnosis.

The easiest way to diagnose erythrasma is to expose the area to ultraviolet light. The light will cause the bacteria causing the infection to fluoresce, resulting in a pink to coral colored glow. Skin scrapings can also be taken and cultured to determine the root cause of the infection. Because of the plethora of similar skin conditions which can be mistaken for erythrasma, it is important to go to a doctor or dermatologist to address skin problems.

Corynebacterium minutissimum is usually the culprit behind erythrasma. To prevent the unsightly condition, people should wash their bodies carefully. Antibacterial soap does not have to be used constantly, but it can be used periodically to remove potentially harmful bacteria from the surface of the skin. Drying thoroughly after bathing can also greatly help to reduce the risk of erythrasma infection.