Keratolysis is the separation or loosening of the stratum corneum (SC), and is part of the natural cycle of skin renewal and regeneration. Disordered keratolysis, resulting in skin overgrowth or excessive desquamation, is responsible for various skin disorders. Keratolytics are agents that cause the separation of the SC through proteolysis of the desmosomes between keratinocytes, and they therefore are often used to treat ailments that manifest in skin overgrowth.
The use of keratolytics dates back to ancient Egypt when hydroxy acids such as lactic, citric and glycolic were commonly used for skin care. In fact, Cleopatra once relied on the keratolytic strength of lactic acid in milk to maintain the youthfulness appearance of her skin. Currently, keratolytics are employed to treat acne vulgaris, psoriasis, seborrheic dermatitis and warts, among other ailments. Specifically, patients afflicted with mild and severe acne utilize keratolytics such as benzoyl peroxide, retinoic acid and salicylic acid to slough off the outermost layers of excess and damaged skin.