Topical salicylic acid is used to help clear and prevent pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat skin conditions that involve scaling or overgrowth of skin cells such as psoriasis (a skin disease in which red, scaly patches form on some areas of the body), ichthyoses (inborn conditions that cause skin dryness and scaling), dandruff, corns, calluses, and warts on the hands or feet. Topical salicylic acid should not be used to treat genital warts, warts on the face, warts with hair growing from them, warts in the nose or mouth, moles, or birthmarks. Salicylic acid is in a class of medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked skin pores to allow pimples to shrink. It treats other skin conditions by softening and loosening dry, scaly, or thickened skin so that it falls off or can be removed easily.