Pulmonary Vasculitides

Vasculitides refer to a heterogeneous set of diseases that are characterized by inflammation of vessel walls that leads to vessel narrowing, necrosis, obliteration, and subsequently to tissue ischemia. Vasculitis can be primary or secondary to another disease entity and can range from affecting only one organ to being a multiorgan systemic disease. Primary vasculitides frequently have some pulmonary manifestations, which may be part of the initial presentation. Discovery of pulmonary artery aneurysms, multiple pulmonary infarcts, and diffuse alveolar hemorrhage should always raise the question of an undiagnosed vasculitis. Takayasu arteritis, also called aortic arch syndrome, middle aortic syndrome, occlusive thromboaortopathy, and nonspecific aortoarteritis, requires a high index of suspicion for an early accurate diagnosis. Giant cell arteritis (GCA) receives its name from its typical histologic pattern. Classically a medium- and large-vessel vasculitis, GCA can affect all vessels of the body but has a predilection for extracranial branches of the carotid artery. Behcet’s disease is a systemic idiopathic vasculitis with recurrent episodes of acute inflammation in multiple organ systems. It is classified as a variable-vessel vasculitis as it can affect small, medium, and large vessels, both arteries and veins. Classically a medium-vessel vasculitis, polyarteritis nodosa is a systemic necrotizing vasculitis that can also affect small vessels. Necrotizing sarcoid granulomatosis is an exceedingly rare type of vasculitis that is usually confined to the lungs and is a diagnosis of exclusion. It is characterized by sarcoid-like granulomas, granulomatous vasculitis, and a variable amount of necrosis. Kawasaki Disease has been reported globally, but there’s a strong geographic and ethnic predominance. The highest incidence is in Japan. The best-established prognostic factor for the most feared complication in those with Kawasaki, coronary artery aneurysms, is age of onset. Isolated pauci-immune capillaritis is a small-vessel vasculitis that is localized to the lung with no other clinical or serologic markers of a systemic disease.