A patient presents with melaena normal renal function, hypeension and mononeuritis multiplex. The most probable diagnosis is:

Answer is A (Classic PAN) : Amongst the options provided, mononeuritis multiplex is a feature of classical PAN and microscopic polyangitis. Presence of hypeension (infrequent in microscopic polyangitis) and normal renal function (infrequent in microscopic polyangitis) leads us to a diagnosis of classical polyaeritis nodosa. Renal involvement in classic PAN Pathology in kidney is that of aeritis without glomeruionephritis (involves small & medium sized muscular aeries) Renal impairment is uncommon-- Hypeension is frequent Renal involvement is mainly in the form of Renovascular hypeension . Renal involvement in microscopic polyangitis Pathology in kidney is that of glomerulonephritis Rapid renal impairment is characteristic-- API 7th/1183 Hypeension is infrequent-API 7th/1183 Causes of mononeuritis multiplex : Common causes Uncommon causes Classic polaeritis nodosa Mixed cryoglobulinemia Microscopic polyangitis Sjogren syndrome RA Wegner's granulomatosis SLE Progressive systemic sclerosis Mixed connective tissue disease Churg-strauss allergic granulomatosis Hypersensitivity angitis Leprosy Amyloidosis Diabetes