Evaluation of the Effects of Corticosteroids on Histamine Release by ex Vivo Cutaneous Microdialysis

The purpose of the study was to evaluate the effects of corticosteroids on histamine release and to compare their potency with the MacKenzie classification based on their vasoconstrictor effects. Thanks to ex vivo cutaneous microdialysis, we studied histamine-induced release over a period of time on excised abdominal skin from women. Eight corticosteroids were topically applied with occlusive dressing onto the skin, above probes, before anti-IgE injection. Histamine levels were assessed by an EIA method. In order to compare the different corticosteroids, AUC was calculated allowing an estimation of the amount of released histamine for 60 min of ex vivo cutaneous microdialysis. Diflucortolone 0.1% and micronized betamethasone dipropionate 0.05% are considered as corticosteroids with high potency in MacKenzie classification. Betamethasone dipropionate associated with propylene glycol 0.05%, belongs to a stronger class in Mackenzie classification. Our results showed that the decrease in histamine release was more important with difluocortolone than with both of these corticosteroids. Therefore there was no correlation between the vasoconstrictor potency of topical corticosteroids and their ability to inhibit histamine release.