allaboutdpt

 Microscopic Polyangiitis Microscopic polyangiitis is a necrotizing vasculitis that generally affects capillaries , as well as small arterioles and venules . It also is called hypersensitivity vasculitis or leukocytoclastic vasculitis . Unlike in PAN ( polyarteritis nodosa ) , all lesions of microscopic polyangiitis tend to be of the same age in any given patient. The skin, mucous membranes , lungs , brain , heart , gastrointestinal tract , kidneys , and muscle all can be involved; necrotizing glomerulonephritis (seen in 90% of patients) and pulmonary capillaritis are particularly common Microscopic angiitis can be a feature of a number of immune disorders, such as Henoch-Schönlein purpura , essential mixed cryoglobulinemia , or the vasculitis associated with connective tissue disorders . In some cases, antibody responses to antigens such as drugs (e.g., penicillin), microorganisms (e.g., streptococci) , heterologous proteins , or tumor proteins have been implicated. Th...