January 25, 2011 Doctor Lawrence Jaeger, Medical Director at Advanced Dermatology Associates provides treatmet options for patients suffering from Pitted Keratolysis. What is the cause of pitted keratolysis? Pitted keratolysis is caused by several bacterial species, including corynebacteria, Dermatophilus congolensis, Kytococcus sedentarius, actinomyces and streptomyces. In moist conditions, the bacteria proliferate. The pitting is due to destruction of the horny cells (stratum corneum) by protease enzymes produced by the bacteria. The bad smell is due to sulfur compounds produced by the bacteria. How is the diagnosis of pitted keratolysis made? Pitted keratolysis is usually diagnosed clinically. Swabs may be helpful to identify causative organisms, and skin scrapings are often taken to exclude fungal infection. The diagnosis is sometimes made by skin biopsy revealing characteristic histopathological features of pitted keratolysis. Treatment of pitted keratolysis Pitted keratolysis can be successfully treated with topical antibiotics such as fusidic acid cream, or with oral erythromycin. It will quickly recur unless the feet are kept dry. Wear boots for as short a period as possible Wear socks which effectively absorb sweat i.e. cotton and/or wool Wear open-toed sandals whenever possible Wash feet with soap or antiseptic cleanser twice daily Apply antiperspirant to the feet at least twice weekly Do not wear the same shoes two days in a row Pitted keratolysis is a descriptive title for a skin condition affecting the soles of the feet. It affects those who sweat profusely (hyperhidrosis) especially if they wear occlusive shoes or boots for long periods. The result is very smelly feet, due to infection of the soles. Either the forefoot or the heel or both become white with clusters of punched-out pits. The appearance is more dramatic when the feet are wet. Very rarely, the fingers are similarly affected. There is a variant of pitted keratolysis where there are more diffuse red areas on the soles. Pitted keratolysis is a non-inflammatory superficial gram positive bacterial infection of the palms and soles, although the latter is most common. Clinically, pitted keratolysis is characterized by small depressions or pits in the top layer of the skin. These pits are typically asymptomatic but can itch or become tender. The species of Corynebacterium and Actinomyces are typically the causative agents. Although pitted keratolysis is frequently associated with excessive sweating and a foul smell, it is not caused solely by the excessive sweating. Rather, perspiration along with tight clothing like socks creates an environment for the bacteria to grow. Treatment includes avoiding tight fitting socks and shoes. Additionally, prescription strength anti-bacterial gels or creams such as clindamycin, erythromycin or mupirocin can be helpful. Sometimes a physician will also prescribe a drying agent such as Drysol.