Definitive: Tissue biopsy
Labs:
Cr, CK, LFTs (elevated)
CBC (Leukocytosis, normochromic anemia, thrombocytosis)
Hepatitis serology
Urinalysis (proteinuria)
ESR/CRP
Imaging
Angiography preferred: aneurysm or stenosis of medium-sized vessels
Arteriograms
CT/MRI
Consider: CXR, blood cultures, autoimmune serologic testing (ANCA, ANA, RF) to rule out other diseases
Cr, CK, LFTs (elevated)
CBC (Leukocytosis, normochromic anemia, thrombocytosis)
Hepatitis serology
Urinalysis (proteinuria)
ESR/CRP
Angiography preferred: aneurysm or stenosis of medium-sized vessels
Arteriograms
CT/MRI
Need at least 3/10 (82% sensitivity and 87% specificity)
Unexplained weight loss greater than 4kg
Livedo reticularis
Testicular Pain or tenderness
Myalgia (excluding shoulder and hip girdle), weakness of muscles, tenderness of leg muscles, or polyneuropathy
Mononeuropathy or polyneuropathy
New-onset diastolic blood pressure > 90mmHg
Elevated serum BUN (>40mg/dL or 14.3mmol/L) or creatinine (>1.5mg/dL or 132 mmol/L)
Evidence of HBV infection (serology)
Characteristic arteriographic abnormalities not resulting fro noninflammatory disease processes
Biopsy of small- or medium-sized artery containing polymorphonuclear cells
Polyarteritis nodosa
Embolism, thrombosis, atherosclerosis
Thromboangiitis obliterans
HIV, Hepatitis, IE, mycotic aneurysm
Takayasu arteritis
Fibromuscular dysplasia
Granulomatosis with polyangiitis
Microscopic polyangiitis, Granulomatosis with polyangiitis 