Inflammatory skin diseases are often treated successfully with topical substances alone. The basic prerequisites for proper treatment are that the specialist has a good knowledge of the products available, their active substances and bases and their relative properties and actions, as well as precise indications for and effects of long-term use. Treatment should be individualized, and best results are usually achieved with a two-phase schedule, beginning mainly with administration of steroids followed by application of nonsteroid products, such as, in psoriasis, anthralin, coal tar, and calcipotriol.