A 42-year-old registered nurse presented with a recurrent history of multifactorial hand dermatitis, which had ceased to respond to the topical corticosteroid that she was using. Patch testing revealed strong reactions to both Advantan Fatty Ointment (Commonwealth Serum Laboratories, Melbourne, Australia), and its active ingredient, methylprednisolone aceponate. Methylprednisolone aceponate is one of the more sensitizing topical corticosteroids and is becoming increasingly recognized as a significant allergen.