Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis. Vasculitis is primarily caused by leukocyte migration and resultant damage. Although both occur in vasculitis, inflammation of veins (phlebitis) or arteries (arteritis) on their own are separate entities.
Possible signs and symptoms include:
General symptoms: fever, unintentional weight loss
Skin: palpable purpura, livedo reticularis
Muscles and joints: muscle pain or inflammation, joint pain or joint swelling
Nervous system: mononeuritis multiplex, headache, stroke, tinnitus, reduced visual acuity, acute visual loss
Heart and arteries: heart attack, high blood pressure, gangrene
Respiratory tract: nosebleeds, bloody cough, lung infiltrates
GI tract: abdominal pain, bloody stool, perforations (hole in the GI tract)
Kidneys: inflammation of the kidney's filtration units (glomeruli)
Vasculitis can be classified by the cause, the location, the type of vessel or the size of vessel.
Underlying cause. For example, the cause of syphilitic aortitis is infectious (aortitis simply refers to inflammation of the aorta, which is an artery.) However, the causes of many forms of vasculitis are poorly understood. There is usually an immune component, but the trigger is often not identified. In these cases, the antibody found is sometimes used in classification, as in ANCA-associated vasculitides. Clinical studies with immunosuppressive drugs targeting specific cytokines and cells can also be used to understand the heterogeneous immunopathogenic mechanisms of vasculitis and support a mechanistic immunological classification.
Location of the affected vessels. For example, ICD-10 classifies "vasculitis limited to skin" with skin conditions (under "L"), and "necrotizing vasculopathies" (corresponding to systemic vasculitis) with musculoskeletal system and connective tissue conditions (under "M").