A patient with disabling keratosis palmaris et plantaris showed a highly favorable response to topical applications of 0.3% vitamin A acid in petrolatum. Obvious clinical improvement as well as marked symptomatic relief were noted within two weeks. On continued daily usage, these beneficial results have been maintained.
Heiss HB, Gross PR. Keratosis Palmaris et Plantaris Treatment With Topically Applied Vitamin A Acid. Arch Dermatol. 1970;101(1):100-103. doi:10.1001/archderm.1970.04000010102020