The axillary, inguinal, post-auricular, and inframammary areas are considered skin folds, where one skin layer touches another. Skin fold areas have a high moisture level and elevated temperature, both of which increase the possibility of microorganism overgrowth. A massive amount of bacteria live on the surface of the skin. Some are purely commensal; thus, only their overgrowth can cause infections, most of which are minor. In some cases, colonization of pathogenic bacteria causes more serious infections. This contribution reviews the bacterial infections of the skin fold areas. (C) 2015 Elsevier Inc. All rights reserved.