{"id":2924,"date":"2010-03-06T22:11:47","date_gmt":"2010-03-07T03:11:47","guid":{"rendered":"http:\/\/insidesurgery.com\/?p=2924"},"modified":"2010-03-06T22:28:17","modified_gmt":"2010-03-07T03:28:17","slug":"polyarteritis-nododa-pan","status":"publish","type":"post","link":"https:\/\/insidesurgery.com\/2010\/03\/polyarteritis-nododa-pan\/","title":{"rendered":"Polyarteritis Nododa (PAN)"},"content":{"rendered":"
Pathophysiology<\/strong><\/p>\n 1)<\/strong> systemic necrotizing vasculitis of small- and medium-sized arteries 2)<\/strong> mostly affects renal, hepatic, and visceral arteries 3)<\/strong> variants – classic polyarteritis nodosa, microscopic angiitis, and Churg-Strauss variant; much overlap among variants 4)<\/strong> classic finding – development of multiple aneurysms along the involved arteries<\/p>\n Signs and Symptoms<\/strong><\/p>\n 1)<\/strong> hypertension 2)<\/strong> renal failure 3)<\/strong> myalgia 4)<\/strong> arthralgia 5)<\/strong> peripheral neuropathy (polyneuropathy multiplex) 6)<\/strong> abdominal pain 7)<\/strong> nausea and vomiting 8)<\/strong> infarction of viscera 9)<\/strong> subcutaneous (skin) red nodules 10)<\/strong> purpura and rash 11)<\/strong> cutaneous infarcts 12)<\/strong> congestive heart failure 13)<\/strong> myocardial infarction 14)<\/strong> fever 15)<\/strong> weight loss 16)<\/strong> headache 17)<\/strong> painful testes<\/p>\n Characteristic Test Findings<\/strong><\/p>\n Laboratory<\/em> – 1)<\/strong> increased leukocyte count 2)<\/strong> anemia 3)<\/strong> increased sed rate 4)<\/strong> positive p-ANCA (but much more common in microscopic angiitis variant) Radiology<\/em> – 5)<\/strong> multiple aneurysms along affected arteries<\/p>\n Histology\/Gross Pathology<\/strong><\/p>\n 1)<\/strong> segmental fibrinoid necrotizing inflammation and occlusion of small- and medium-size arteries, especially at branch points 2)<\/strong> microscopic angiitis – also associated with venitis and pulmonary and bronchial artery involvement (not seen in classic variant)<\/p>\n Associated Conditions<\/strong><\/p>\n 1)<\/strong> variants overlap and there is inexactness as to defining parameters of each disease 2)<\/strong> hepatitis B antigen occurs in 30% of cases of classic variant and hepatitis C antigen occurs in 5% 3)<\/strong> increased incidence in hairy cell leukemia<\/p>\n Biochemistry<\/strong><\/p>\n likely immunologic component as circulating hepatitis B antigen\/IgM complexes found in walls of affected blood vessels<\/p>\n Treatment<\/strong><\/p>\n 1)<\/strong> prednisone 2)<\/strong> cyclophosphamide 3)<\/strong> (vidarabine) antihepatitis B treatment 4)<\/strong> plasmapheresis 5)<\/strong> alpha-IFN<\/p>\n Tips for USMLE<\/strong><\/p>\n 1)<\/strong> if question mentions granulomas, it is not PAN 2)<\/strong> if eosinophils are mentioned, it is not PAN 3)<\/strong> if question mentions multiple aneurysms in hepatic, renal, or mesenteric arteries, think PAN (although this is not strictly pathognomonic)<\/p>\n","protected":false},"excerpt":{"rendered":" Pathophysiology 1) systemic necrotizing vasculitis of small- and medium-sized arteries 2) mostly affects renal, hepatic, and visceral arteries 3) variants – classic polyarteritis nodosa, microscopic angiitis, and Churg-Strauss variant; much overlap among variants 4) classic finding – development of multiple aneurysms along the involved arteries Signs and Symptoms 1) hypertension 2) renal failure 3) myalgia […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[63,1],"tags":[1428,1427,1429,1426,1431,1432,1430],"yoast_head":"\n