DIFFUSE ALVEOLAR HAEMORRHAGE- A RARE CASE OF p-ANCA POSITIVE VASCULITIS

Diffuse alveolar haemorrhage (DAH) is defined as haemorrhage into the pulmonary microvasculature rather than parenchyma or airways with a catastrophe of events leading to haemoptysis, falling haematocrit, hypoxemia, respiratory failure and diffuse pulmonary infiltrates (1). It should be considered as a medical emergency because of high morbidity and mortality. Annual incidence is upto 2 to 4 cases per million population. Pulmonary renal syndromes , connective tissue disorders and drugs make up most of the cases of DAH. Histologically DAH is recognized with pulmonary capillaritis.(2) Most common autoimmune causes include goodpasture syndrome, small vessel vasculitis and SLE. The non-immune causes of DAH are tumors, coagulopathy, and pulmonary thromboembolism. The mean age of presentation of small vessel vasculitis is 40 to 50 years with equal male female preponderance. This case report identifies diffuse alveolar hemorrhage as a presentation of pulmonary renal syndrome in a young female presenting with haemoptysis. However one third of diffuse alveolar hemorrhage cases may not have haemoptysis (3). HRCT findings can vary with time of onset of heamorrhage and the clinical context is crucial in imaging interpretation. In acute stage can range from ground glass opacities to consolidation due to alveolar filling with blood and in subacute stage within 2-3 days , intralobular lines interlobular septal thickening and crazypaving pattern can be seen. Chronic stage shows ill defined centrilobular nodules reflecting intra alveolar accumulation of pulmonary macrophages.