Pulmonary vasculitis are observed in vasculitic syndromes that preferentially affect small vessels (arterioles, venules, and capillaries). They include the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (Wegener's granulomatosis, Churg-Strauss syndrome, and microscopic polyangitis) that share histologic similarities without immune deposits; anti-glomerular basement membrane (GBM) disease; Henoch-Schönlein purpura and cryoglobulinemia vasculitis. Vasculitic syndromes that affect large/medium vessels (such as Kawasaki's disease, polyarteritis nodosa) only occasionally affect the lung [111] . Wegener's granulomatosis Wegener's granulomatosis (WG) is a rare disease of uncertain cause. It seems to affect children as much as adults with an increasing reported incidence around 2.75 cases/million/year, mostly in teenagers with a reported median age of 14.2 years (4-17 years) [112, 113] . It is characterized by inflammation in a variety of tissues including blood vessels (vasculitis). WG primarily affects the upper respiratory tract, lung, and kidneys. The diagnosis is based on the combination of symptoms and a biopsy of affected tissue with necrotising granulomatous vasculitis in the absence of an infectious etiology. The diagnosis is further supported by positive blood tests for cytoplasmic-staining (c)-ANCA PR3 type [114] .