Prolonged treatment with topical glucocorticoids results in an inhibition of the allergen-induced weal-and-flare response and a reduction in skin mast cell numbers and histamine content.
The inhibitory effects of topical glucocorticosteroid treatment on the immediate dermal allergic reaction were studied in 10 patients in a double, randomized, placebo-controlled fashion. The aim was to study whether a prolongation of the treatment time would enhance the inhibitory effect beyond the 30-40% reduction previously reported after 1 week of treatment, and whether any changes in skin reactivity were accompanied by changes in the level of mast cells or histamine at the challenge site. Allergen and histamine skin-prick tests were performed on both forearms before the start of the study and after 2 and 4 weeks of treatment with placebo cream on one forearm and with 0.05% clobetasol-17-propionate cream on the other. Punch biopsies from the skin treated actively and with placebo were taken after 4 weeks in eight of the patients. The specimens were used for the light-microscopic evaluation of mast cell density and for the measurement of histamine and protein content. After 4 weeks of treatment we found a reduction in the allergen-induced weal (72%; P less than 0.001) and flare (62%; P less than 0.05) response. There was also a minor reduction in the histamine-induced weal (38%; P less than 0.05) but not the flare response, suggesting that the glucocorticoid treatment induced a reduced mediator release at allergen challenge. This could be partially explained by the finding of a reduction in the number of detectable skin mast cells (85%; from 0.78 to 0.11 mast cells per unit area) and in the histamine content of the skin as related to the tissue wet weight (36%; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Pipkorn
U
U
ENT Department, University Hospital, Lund, Sweden.
Hammarlund
A
A
Enerbäck
L
L
D000328:Adult; D001623:Betamethasone / Q000031:analogs & derivatives*; D002452:Cell Count; D002986:Clinical Trials as Topic; D002990:Clobetasol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003877:Dermatitis, Contact / Q000517:prevention & control*; D004311:Double-Blind Method; D006632:Histamine / Q000032:analysis*; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000187:drug effects*; D010919:Placebos; D011506:Proteins / Q000032:analysis; D011897:Random Allocation; D012867:Skin / Q000032:analysis / Q000473:pathology*; D012882:Skin Tests
D010919:Placebos; D011506:Proteins; D006632:Histamine; D001623:Betamethasone; D002990:Clobetasol