Severe Disabling Myalgia as an Initial Presentation of Polyarteritis Nodosa

Abstract

Background. Polyarteritis nodosa (PAN) is a form of necrotizing vasculitis affecting medium or small blood vessels with multiorganinvolvement.AlthoughmyalgiaisaclinicalfeatureofPAN,severedisablingmyalgiaastheinitialpresentationisrarely noted. Case Presentation. We present a case of 54-year-old male with recently detected chronic kidney disease admitted with progressive severe disabling muscular pains predominantly over calves with constitutional symptoms for seven weeks. He was weak tomobilizeoutofthebed.Later,hedevelopedavasculiticrash,unilateralulnarclaw,andbilateralfootdrop.Hisskinand muscle biopsies showed evidence of vasculitis. His renal and mesenteric artery CTangiogram revealed stenosed segment of the celiac artery without evidence of visible aneurysms elsewhere. He completed six cycles of intravenous cyclophosphamide pulse therapy with high-dose oral prednisolone with good response. With continuation of aggressive immunosuppression and rehabilitation for five months, the patient improved and was able to walk without support. Conclusion. Musculoskeletal predominantPAN,eventhoughrare,needstobeconsideredinpatientspresentingwithdisablingmusclepainandweakness.These features may herald over days to months along with constitutional symptoms before other systems getting affected. Early recognition of such symptoms and initiating specific treatment would be important for better outcomes.