Abstract
The aetiopathogenesis of pityriasis lichenoides (PL) is still far from clearly understood. However, the involvement of delayed-type immune dysfunctions has recently been hypothesized. On the basis of this premise, and in view of the recognized immunomodulating effects of synthetic derivatives of vitamin A, an open trial was carried out of the efficacy and tolerability of oral etretinate in four men, aged 21 to 49 years, with PL. With a daily dosage of 1 mg/kg, full resolution was achieved in 6-18 weeks. The overall tolerability was good, with mild to moderate mucocutaneous side-effects. The relapse-free period had currently reached 8-12 months. Oral etretinate seems to be a promising therapeutic tool in the management of PL, for which to date no definitive treatment exists.