A pediatric case of pityriasis rubra pilaris successfully treated with low-dose vitamin a.

Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory keratosis that is clinically characterized by gradually developing reddish or orange extending plaques and keratotic follicular papules. In pediatric patients, we frequently hesitate to administer certain medications for treatment of PRP, specifically etretinate, systemic corticosteroids, and biologics recommended by previous studies. Although administration of high-dose vitamin A was described in a previous textbook of dermatology, details about the lower limits and treatment periods were not provided. We presented a pediatric case of PRP that was successfully controlled with minimum dosage of systemic vitamin A in the literature. Before and 14 days after beginning the therapy, both vitamin A levels of peripheral blood were within the normal range. We considered that the clinical efficacy may not be due to a supplementary effect of vitamin A, but to a pharmacological action because serum vitamin A was within the normal limits during the therapy.