Sensitivity of different areas of the flexor aspect of the human forearm to corticosteroid-induced skin blanching.

The intensity of corticosteroid-induced blanching has been found to vary at different areas of the flexor aspect of the human forearm. A retrospective analysis of 38,880 observations of skin blanching in 56 volunteers was conducted to assess the sensitivity of forearm skin to betamethasone 17-valerate. The mid-forearm appears to be more sensitive to the blanching response than do the areas close to the wrist or elbow. These results indicate that each preparation under evaluation should be applied to several sites along the forearm when using the human skin blanching assay in order to obtain an accurate comparative assessment of corticosteroid release from topical delivery vehicles.