Therapeutics in dermatology underwent complete change after the introduction of topical hydrocortisone in the Fifties. At the time, stronger derivatives than hydrocortisone were synthetised and the indications for topical corticosteroids were expanded. Around twenty different molecules, classified according to their strength, are currently available for prescription in France. Many inflammatory or tumoral skin diseases respond to these products. The choice of a topical corticosteroid (strength, vehicle...) and of its mode of application (technique, rhythm of application) is oriented by the context (dermatitis treated, localization) and must respect "Good clinical practice" guidelines so as to select the best benefit/risk ratio.