Hypersensitivity to topical corticosteroids is a common cause of allergic contact dermatitis, The development of contact allergy is dependent on individual susceptibility, exposure to the potential allergen and the ability to penetrate the epidermis and react with epidermal protein, We looked at corticosteroid binding to arginine and relative usage of corticosteroids to see if these variables explain the number of allergic reactions seen to these structurally similar chemicals. A linear relationship was found between a measure of corticosteroid binding to arginine, the log of relative corticosteroid usage and the log of the relative number of corticosteroid allergies, Using multiple regression this association was significant (P = 0.01), Statistically, these two variables accounted for 73% of the variation in the results, Our results showed that the number of corticosteroid allergic reactions was dependent on usage and the intrinsic ability of the corticosteroid to degrade and bind to arginine, While total corticosteroid usage is unlikely to change, the prescription of individual corticosteroids with a reduced potential to degrade and bind to protein, but with equal efficacy, might reduce the overall prevalence of corticosteroid hypersensitivity.