Nine patients with palmoplantar keratoderma were treated with vitamin A acid (retinoic acid) 0.1% in petroleum jelly and all improved. In the acquired forms the cure seems to have been permanent. Patients with genetic palmoplantar keratoderma remain free of symptoms without any side-effects by the use of vitamin A acid, topically applied once or twice weekly.
Günther SH. Vitamin A Acid in theTreatment of Palmoplantar Keratoderma. Arch Dermatol. 1972;106(6):854-857. doi:10.1001/archderm.1972.01620150040013