Evaluation of 13-cis retinoic acid in lamellar ichthyosis, pityriasis rubra pilaris and Darier's disease.

A new synthetic oral retinoid, 13-cis retinoic acid, is fairly well tolerated in patients and appears to be effective in those with Darier's disease and lamellar ichthyosis. It is less effective in those with pityriasis rubra pilaris. The mechanism of action of 13-cis retinoic acid in disorders of keratinization is unknown at the present time; however, it does not appear to cause lysosomal proliferation in therapeutic doses.