Maintenance therapy in the interval between flares is an essential part of the therapeutic approach to psoriasis. The therapeutic effectiveness of maintenance therapy results from a positive influence on the physicochemical characteristics of individual compartments of the skin, especially the stratum corneum and the epidermis. The objective is revert from a pathological milieu toward a physiological one. These effects may be supplemented by pharmacological or biochemical effects of the active substances or substance mixtures. Focal points are the use of lipophilic bases as well as keratoplastic, antiseptic and antipruriginous additives.