[Local treatment with corticosteroids--limits on the duration of administration]

In local therapy with corticosteroids, undesirable effects are closely related to the duration of the treatment. These interactions are even more evident if the tolerance of different corticosteroids varying in strength of action is examined and referred to the duration of application. For example, symptoms of epidermal atrophy may occur even after as little as 4 weeks' treatment with very potent antiproliferative corticosteroids, whereas with the only moderately active hydrocortisone, which has an exclusively anti-inflammatory effect, these symptoms are hardly observed even after 10 weeks of application. The question of the origin of these undesirable effects is considered in post-marketing studies, for example, and in particular the question of when they are attributable, solely to the vehicle and when to the corticoid itself, is discussed. In addition, an attempt is made to classify the corticosteroids into those for which the permissible duration of treatment must be specified in the package insert and those for which this does not seem necessary. In this connection, the treatment periods required with fixed combinations are discussed with reference to the basic skin disease. Finally, the duration of treatment when application is limited to certain cutaneous areas or to a certain size of skin area or when the treatment is self-prescribed is discussed.