In a study of more than 60 substances chosen for their possible antikeratinogenic properties, Van Scott and Yu [1] found that the most effective drug belongs to the group of alpha-hydroxy acids. A three times a day application of citric, glycolic, lactic, malic, pyruvic and glucuronic acid, for instance, gave excellent results in all forms of ichthyosis except epidermolytic hyperkeratosis. The substances were applied at 5% strength in a hydrophilic ointment, though the base was a matter of the patient’s preference. Sustained remission was obtained as long as the treatment continued. The use of these agents has been extended to other hyperkeratotic conditions. Glycolic acid became available in the late 1980s as a peeling agent.