Pulmonary vasculitis

Vasculitides are a heterogeneous group of diseases characterised by the inflammation and destruction of vessel walls, which reduces blood flow into tissues. These diseases are classified according to the affected organ and size of the vessels involved (1-4). Vasculitides can be primary or secondary to connective tissue disease, infection, neoplasm, or to a state of hypersensitivity (5). Primary vasculitides are rare diseases with an approximate incidence of 20–100 cases/million/year and a prevalence of 150–450 cases/million (5-7). Small-vessel vasculitides associated with antineutrophil cytoplasmic antibodies (ANCAs) generally affect the lungs