CD04 An unusual case of menorrhagia and an episodic rash

Abstract

Abstract A 24-year-old female university student from Hong Kong was referred with a 4-month history of a vesicular rash on her lips, eyes and oral mucosa that always appeared around the same time of her menstrual cycle. She would also get similar lesions on her neck, arms and legs. She was seen in dermatology and given a provisional diagnosis of erythema multiforme/recurrent herpes simplex and started on treatment, as well as prophylactic dose aciclovir for a few months. Despite this, there was no improvement in symptoms and her viral swabs also came back negative. She was referred for a second opinion, and, on reviewing her history, she volunteered that she suffers from menorrhagia. On questioning regarding any use of painkillers, she took out a packet of 60-mg etoricoxib that she had been getting from Hong Kong over the counter (OTC) and which was not on her records in the UK. She was taking this on day 1 of her period, and the vesicular eruption appeared the following day; it also became apparent that it would occur at the same sites on her body each time. A fixed drug eruption (FDE) to etoricoxib was suspected, and patch testing was undertaken to our baseline, facial and photopatch series (which includes a number of nonsteroidal anti-inflammatory drugs), to the medication crushed in paraffin applied to the back as standard and also to the specific sites at which the eruptions occur on the neck, arms and legs (lesional skin) under occlusion. No reactions were seen at 48 h, but at 72 h, we noted vesicular eruptions morphologically identical to the very dramatic photos she had on her phone but only in the areas where she had previously reacted (lesional skin); no reaction was seen on the nonlesional skin on the back where the standard patch testing was performed. Her rash fully resolved after stopping the etoricoxib. This case highlights the importance of enquiring about OTC medications when seeing patients with unusual or recalcitrant presentations as the flare with the menstrual cycle was a red herring and also highlights the importance of patch testing lesional skin with the culprit medication to avoid false negatives when considering FDE. This is a rare presentation of a FDE to etoricoxib, with only eight other cases reported in the literature, but this should be considered as a differential diagnosis in someone presenting with an erythema multiforme-like eruption.