PT - JOURNAL ARTICLE AU - Sara Todo Bom Costa AU - InĂªs Salas Sanmarful TI - Primary amenorrhoea as a manifestation of coeliac disease AID - 10.1136/bcr-2020-239260 DP - 2021 Jan 01 TA - BMJ Case Reports PG - e239260 VI - 14 IP - 1 4099 - http://casereports.bmj.com/content/14/1/e239260.short 4100 - http://casereports.bmj.com/content/14/1/e239260.full SO - BMJ Case Reports2021 Jan 01; 14 AB - Coeliac disease is a systemic autoimmune disorder that has a wide range of clinical manifestations that include abdominal pain, diarrhoea, obstipation, weight loss, short stature and even primary amenorrhoea. It can be asymptomatic, which makes it an underdiagnosed disease. We present a case report of a 15-year-old girl who was referred to a paediatric consultation due to primary amenorrhoea. A detailed clinical history revealed poor weight gain. Physical examination showed that secondary sexual characteristics were present and there was a low body mass index. Ultrasonography images and laboratory tests revealed a normal urogenital system and an adequate gonadal function. Coeliac disease antibodies were positive and the diagnosis was confirmed through duodenal biopsy. The symptom resolved with a gluten-free diet. An approach to primary amenorrhoea should always include investigation of a systemic illness as it is a rare but treatable diagnosis.