The development from the discovery of the structure of cholesterol, the precursor of all steroids, to the first application of a topically effective steroid in 1952 took about 20 years. Thereafter the development of more potent topically effective steroids accelerated and the third generation of potent steroids with a topical activity of about 10 to 20 times that of hydrocortisone was already available about 10 years later. Today the newly developed non-fluorinated non-symmetric 16 alpha, 17 alpha-acetal derivate budesonide could perhaps be considered as the sixth generation.