Collapse is a commonly encountered problem in the emergency department. Its causes are many and varied, and some are potentially life threatening.1 In this interactive case report, Mrs Barroso presented with recurrent collapses coinciding with the onset of menstruation.2 Given her rapid response to steroids, I would have thought initially that she had adrenal insufficiency. In fact, most of the respondents on bmj.com concluded the same.3 Based on the lack of response to vasoactive drugs, I would have discarded a diagnosis of anaphylaxis. Corticosteroids are usually …