I have a pimply rash on my but?

Skin Infection: Given the danger of the current epidemic of staph infections i think this is a question best answered in person at your doctor's office. Skin troubles are not well handled in the cyber world.

Pimples on buttocks: Two common rashes that look like pimples on buttocks: 1. Keratosis pilaris-white hard papules in hair follicles common in people with sensitive dry skin. Responds well to lotions with Alpha hydroxy acids. 2. Folliculitis/acne-pustules in hair follicles. Made worse by heat and friction. May respond to benzoyl peroxide wash or prescription antibiotic lotion. Please see dermatologist for diagnosis.