Vasculitis: A general term for a group of uncommon diseases that feature inflammation of the blood vessels. Each of the vasculitis diseases is defined by characteristic distributions of blood vessel involvement, patterns of organ involvement, and laboratory test abnormalities. The actual causes of these vasculitis diseases are usually not known, but immune system abnormality is a common feature. Examples of vasculitis include Kawasaki disease, Behcet's disease, polyarteritis nodosa, granulomatosis with polyangiitis, Takayasu's arteritis, Churg-Strauss syndrome, giant cell arteritis (temporal arteritis), and Henoch-Schonlein purpura. Vasculitis can also accompany infections, such as hepatitis B; exposure to chemicals, such as amphetamines and cocaine; cancers, such as lymphomas and multiple myeloma; and rheumatic diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Laboratory testing in a patient with active vasculitis generally indicates inflammation in the body, and depending on the degree of organ involvement, a variety of organ function tests can be abnormal. The ultimate diagnosis for vasculitis is typically established after a biopsy of involved tissue demonstrates the pattern of blood vessel inflammation. Treatment depends on the type and severity of the illness and the organs involved. Treatments are generally directed toward stopping the inflammation and suppressing the immune system. Typically, cortisone-related medications, such as prednisone, are used, as are other immune-
suppression drugs, such as cyclophosphamide (brand name: Cytoxan). Also known as angiitis and vasculitides (the plural form of vasculitis).
