Table 2.

Differential diagnosis for WG

Condition	Feature	Vascular involvement	Diagnosis	Comments
Churg-Strauss syndrome	Usually associated with asthma	Necrotising vasculitis affecting small to medium sized vessels	Eosinophilia and p-ANCA will be elevated	In WG c- ANCA will be high
Microscopic polyarteritis	Necrotising glomerulonephritis common	Mainly small vessel vasculitis	Negative for PR 3	Antiglomerular antibody will ne negative
Temporal arteritis	>50 years Head ache, jaw claudication	Granulomatous arteritis aorta and its major branches, especially extra cranial branches of carotid artery	Often affects temporal artery	Temporal artery biopsy is negative in 50%
Takayasu's arteritis	Absent upper limb pulses, systemic features such as fever, weight loss and joint pains	Granulomatous inflammation of aorta and its major branches Periaortitis, aortic dissection aneurysm and thrombosis of subclavian left gastric, hepatic and renal artery aneurysms	Diagnosis based upon American college of rheumatology criteria	Mainly affects Asian women
Ankylosing Spondylytis	Chronic back pain in young	5% can get aortitis Patchy destruction of both muscle and elastic tissue of media Fibrosis of intima	Radiologically there will sacroilitis	Seronegative arthropathy