[Practical application of local corticotherapy: topical corticosteroids].

Topical corticosteroids are mainly used for their anti-inflammatory activity by a complex mechanism Which involves vasoconstriction, inhibition of leucocyte migration and stabilization of lysosomal membranes with inhibition of inflammation factors synthesis. In non-inflammatory skin diseases, they are used for their antimitotic effect or their ability to inhibit the synthesis of several macromolecules forming the connective tissue. So many topical corticosteroids are now available that they must be classified according to their level of activity, as measured by a vasoconstriction test. The European classification system has four levels numbered I to IV in descending order of potency. The choice of activity level depends on the patient's age and on the location, extent and acute or chronic character of the lesions. Creams are the most versatile preparations. Topical corticosteroids are contra-indicated in all infective skin diseases. Penetration through the skin varies according to the corticosteroid utilized, to the state of the skin on which it is applied and to the modalities of its applications. Irreversible skin atrophy is usually observed only after prolonged use of topical steroids levels I and II.