[Treatment with retinoids]

Aromatic retinoids are synthetic vitamin A derivatives that are particularly active in the treatment of severe psoriasis. They have two pharmacodynamic properties: a regulating effect on epidermal differentiation, and an immunomodulating effect, notably on some functions of granulocytes. Two compounds from this group are now available: etretinate (Tigason) and its active metabolite and future successor acitretin (Soriatane). Retinoids are indicated in pustular psoriasis, erythrodermic psoriasis and extensive psoriasis vulgaris. The mean daily dose in adults is 30 to 50 mg for etretinate and 30 to 35 mg for acitretin. The dose-dependent cutaneous and mucosal side-effects consist of dryness of mucous membranes, desquamation of the extremities and fragility of the skin. Laboratory tests for liver function and lipids must be performed regularly. Because of their teratogenicity, retinoids are strictly contra-indicated in pregnant women and otherwise require and efficient contraception pursued for at least two years after withdrawal of etretinate or acitretin therapy.