Allergic contact dermatitis from topical corticosteroids is not uncommon. Budesonide has been included in the European standard series as a marker for corticosteroid allergy, though little is known of its cross-reactivity with other corticosteroids. Twelve patients previously positive to budesonide on patch testing were given further patch and intradermal tests to a range of corticosteroids. Six patients previously negative to budesonide on patch testing were used as a control group. Budesonide cross-reacts with hydrocortisone-21-sodium phosphate and triamcinolone acetonide. Patients positive to budesonide should therefore avoid hydrocortisone and triamcinolone acetonide. Patch testing, unfortunately, is an inaccurate method of determining cross-reactivity patterns among corticosteroids.