PT - JOURNAL ARTICLE AU - Sandra Isabel Correia AU - Isabel Eira AU - Andre Santa Cruz AU - Cristina Ângela TI - Pulmonary–renal syndrome: diagnostic challenge AID - 10.1136/bcr-2018-227720 DP - 2019 Apr 01 TA - BMJ Case Reports PG - e227720 VI - 12 IP - 4 4099 - http://casereports.bmj.com/content/12/4/e227720.short 4100 - http://casereports.bmj.com/content/12/4/e227720.full SO - BMJ Case Reports2019 Apr 01; 12 AB - Vasculitis presents several diagnostic challenges. Herein, we present a clinical case of a 71- year old woman, observed in our emergency department due to asthenia, vomiting and persistent cough. The patient had a history of progressive renal failure and anaemia over the last years. On physical examinations, fine pulmonary crackles were detected and laboratory test showed haemoglobin 69 g/L, creatinine 4 mg/dL, potassium 6.3 mmol/L, positive antineutrophil cytoplasm antibody (ANCA), with proteins and dimorphic erythrocytes in the urinary sediment. CT analysis of the thorax revealed patchy ground glass haziness, likely due to diffuse alveolar haemorrhage. Pulmonary–renal syndrome was assumed, and induction therapy was initiated. She was discharged after 33 days of hospitalisation. On the following months, ANCA titres remained undetectable, but minor recovery of renal function was observed, requiring haemodialysis. Indeed, the use of aggressive induction therapy at early stage dramatically improve prognosis, maintenance of disease remission may be difficult, as relapse is frequent.