Necrotizing vasculitis, also called systemic necrotizing vasculitus, is a category of vasculitis, comprising vasculitides that present with necrosis.Examples include giant cell arteritis, microscopic polyangiitis, and granulomatosis with polyangiitis. ICD-10 uses the variant "necrotizing vasculopathy". ICD-9, while classifying these conditions together, does not use a dedicated phrase, instead calling them "polyarteritis nodosa and allied conditions". When using the influential classification known as the "Chapel Hill Consensus Conference", the terms "systemic vasculitis" or "primary systemic vasculitides" are commonly used. Although the word necrotizing is omitted, the conditions described are largely the same. Classification
Large vessel vasculitis
Giant-cell arteritis and Takayasus arteritis have much in common, but usually affect patients of different ages, with Takayasus arteritis affecting younger people, and giant-cell arteritis having a later age of onset. Aortitis can also be considered a large-vessel disease.Takayasu arteritis. Primarily affects the aorta and its main branches. At least three out of six criteria yields sensitivity and specificity of 90.5 and 97.8%:

Onset < 40 years affects young and middle -aged women (ages 15–45)
Claudication of extremities
Decreased pulsation of one or both brachial arteries
At least 10 mmHg systolic difference in both arms
Bruit over one or both carotid arteries or abdominal aorta
Arteriographic narrowing of aorta, its primary branches, or large arteries in upper or lower extremities
Ocular manifestation
Visual loss or field defects
Retinal hemorrhages
Neurological abnormalities
Treatment: steroidsGiant cell (temporal) arteritis. Chronic vasculitis of both large and medium vessels, primarily affecting cranial branches of the arteries arising from the aortic arch.
At least three out of five criteria yields sensitivity and specificity of 95 and 91%: 

Age at onset ≥ 50 years
New onset headache with localized tenderness
Temporal artery tenderness or decreased pulsation
Elevated ESR ≥ 50 mm/hour Westergren
Temporal artery biopsy showing vasculitis with mononuclear cell infiltrate or granulomatous inflammation, usually with multinucleated giant cells

Medium vessel vasculitis
These conditions are sometimes considered together with the small vessel vasculitides.Polyarteritis nodosa (PAN). Systemic necrotizing vasculitis and aneurysm formation affecting both medium and small arteries. If only small vessels are affected, it is called microscopic polyangiitis, although it is more associated with granulomatosis with polyangiitis than to classic PAN. At least 3 out of 10 criteria yields sensitivity and specificity of 82 and 87%:

Unexplained weight loss > 4 kg
Livedo reticularis
Testicular pain
Myalgias, weakness
Abdominal pain, diarrhea, and GI bleeding
Mononeuropathy or polyneuropathy
New onset diastolic blood pressure > 90 mmHg
Elevated serum blood urea nitrogen (> 40 mg/dL) or serum creatinine (> 1.5 mg/dL)
Hepatitis B infection
Arteriographic abnormalities
Arterial biopsy showing polymorphonuclear cellsKawasaki disease. Usually in children (age<4), it affects large, medium, and small vessels, prominently the coronary arteries. Associated with a mucocutaneous lymph node syndrome. Diagnosis requires fever lasting five days or more with at least four out of five criteria:

Bilateral conjunctival injection
Injected or fissured lips, injected pharynx, or strawberry tongue
Erythema of palms/soles, edema of hands/feet, periungual desquamation
Polymorphous rash
Cervical lymphadenopathy (at least one node > 1.5 cm)Isolated cerebral vasculitis. Affects medium and small arteries over a diffuse CNS area, without symptomatic extracranial vessel involvement. Patients have CNS symptoms as well as cerebral vasculitis by angiography and leptomeningeal biopsy.