Ranking of glucocorticoid creams and ointments

20 corticosteroids ointments and 19 corticosteroid creams available on the Swedish market in January 1977 were tested for their blanching effect. Three ointments and three creams showing pronounced blanching were tested only without occlusion. Hydrocortisone preparations were tested only with occlusion. Other preparations were tested with and without occlusion. All ointments and creams were tested at four randomized sites on the flexor aspect of the forearm in each of 11 or 12 subjects. When used occlusion was applied for 6 hours. Repeated readings were made, using scores 0, 1, 2, and 3. The reading at the time when most preparations showed blanching were analysed statistically. The scores for blanching showed a Poisson distribution when the mean score was less than or equal to 1. Classification of preparations according to blanching was facilitated by the fact that statistical methods for Poisson distribution could be used. A ranking of corticosteroids based on vasoconstriction was obtained, and four different groups for ointments and four for creams emerged. The arbitrary nature of any ranking and grouping of steroids is evident from the data presented.