Topical corticosteroid allergy in an urban Australian centre

The reported prevalence of allergic contact dermatitis from topical corticosteroids in clinical populations, in the period 1993-2002, varied from 0.55 to 5.98%. This study is a retrospective analysis of 1153 individuals undergoing routine patch testing in an Occupational Dermatology Clinic in Melbourne, Australia. We report a rate of 0.52% for positive patch test reactions to 5 corticosteroids. Corticosteroids tested were betamethasone-17-valerate, budesonide, Diprosone(R) cream (betamethasone diproprionate 0.05%) (Essex-Pharma, a division of Schering-Plough Pty Ltd, Sydney, Australia), tixocortol-21-pivalate and triamcinolone acetonide. Population characteristics were described using the MOAHL (M = percentage of males tested; O = occupational; A = atopics; H = patients with hand eczema; L = patients with leg ulcers or stasis eczema) index. Prescribing patterns, rate of referral and rate of relevant positive patch test reactions were characterized for the region. These results were compared to the rates of corticosteroid allergy and patch testing methodologies from published international studies. It was noted that many high-sensitization potential corticosteroids were not available in our region. Although a low percentage of leg ulcers and stasis dermatitis may be associated with a lower rate of corticosteroid allergy, this association may be confounded by regional factors such as prescribing habits and the local availability of corticosteroids. We conclude that the low rate of topical corticosteroid contact allergy reported by our clinic is associated with regional availability and prescribing practices and the scarcity of stasis dermatitis and leg ulcers in our clinic population.