TY - JOUR T1 - Syndrome of inappropriate antidiuretic hormone associated with eosinophilic granulomatosis and polyangiitis JF - BMJ Case Reports JO - BMJ Case Reports DO - 10.1136/bcr-2019-231249 VL - 13 IS - 3 SP - e231249 AU - Michael S Lundin AU - Beenu Kaw AU - Rajit Pahwa Y1 - 2020/03/01 UR - http://casereports.bmj.com/content/13/3/e231249.abstract N2 - A 62-year-old man presented with classic signs and symptoms of eosinophilic granulomatosis and polyangiitis (EGPA, also known as Churg-Strauss syndrome)—mononeuritis multiplex, palpable purpura, hypereosinophilia, positive P-ANCA (perinuclear anti-neutrophil cytoplasmic antibodies) developed diffuse alveolar haemorrhage. The patient had longstanding mild hyponatraemia, but developed moderate and symptomatic hyponatraemia characteristic of the syndrome of inappropriate antidiuretic hormone. The patient’s serum sodium returned to his baseline- mildly hyponatraemic, after initiation of treatment targeted towards EGPA. ER -