Rapidly worsening pneumonia in a middle-aged woman: a rare diagnosis and a crucial management decision.

A 54-year-old Indian female presented to the hospital with a 4-day history of fever, shortness of breath and blood-streaked sputum. Chest radiograph showed consolidation and she was admitted as a case of bilateral bronchopneumonia. She was started on broad-spectrum antibiotics and antivirals but she continued to deteriorate clinically with increasing oxygen requirement and worsening lung infiltrates. Since lab investigations also revealed significant anaemia and renal impairment, vasculitic workup for pulmonary renal haemorrhagic syndrome was ordered even though she had no haemoptysis in the hospital and haemoglobin was stable after initial blood transfusion. High-resolution computed tomography scan was done on day 5 to assess progression and for any clue to diagnosis. It showed extensive bilateral air space consolidation and ground-glass opacities with suggested radiological differential diagnosis of cryptogenic organising pneumonia or pulmonary haemorrhage. Pulmonology team did not recommend bronchoscopy at the time.In view of the clinical features of rapidly progressing pneumonia despite standard treatment, history of haemoptysis, anaemia, renal impairment and CT scan findings suggestive of pulmonary haemorrhage, pulse intravenous Methylprednisolone was initiated. The patient showed marked clinical and radiological improvement. The vasculitic workup later revealed positive myeloperoxidase antibody and a definitive diagnosis of microscopic polyangiitis was made. She was discharged in a stable condition and advised to follow-up in rheumatology where she continues to follow-up 2 years after her initial diagnosis.This is the first case reported in literature, where treatment was initiated for this rare disease entity within a week of presentation based on highly suggestive clinical, laboratory and radiological evidence without waiting for a confirmatory diagnosis. Delay in this rapidly deteriorating patient could have been fatal and our prompt action was crucial in securing a favourable outcome.