Case Presentation: A 65-year-old male with a past medical history of hypersensitivity pneumonitis/bronchiolitis, coronary artery disease, hypertension and hyperlipidemia was admitted for uncontrolled pain. Myalgias and fatigue were present for a month following a tick bite and shingles. He was treated with doxycycline 100mg twice a day for 14 days and valacyclovir 1g three times a day for 7 days, respectively. Two days prior, he was discharged from another hospital with prednisone for suspected autoimmune disease.On admission, the patient was hypertensive up to 200/112, improving after pain medication. ED workup was notable for WBC count of 22,900/mL, sodium of 126 mEq/L, CRP of 13.45 and ESR of 34. Two days into admission, he transferred to the ICU for acute hypoxemic respiratory failure. CT found small bowel obstruction and left pulmonary nodular amyloidosis. Brain MRI revealed acute/subacute ischemia of left caudate nucleus, external capsule and centrum semiovale. The patient developed abdominal pain and focal peritonitis so combined with prior CT results, laparotomy exploration was performed with small bowel resection due to full-thickness necrosis. His stay was complicated by acute kidney injury secondary to acute tubular necrosis, evidenced by worsening creatinine and continued hyponatremia. Echocardiogram was unremarkable suggesting a non-embolic diagnosis. Testing showed c-ANCA with a titer of 1:40 and positive myeloperoxidase (MPO). p-ANCA, ANA screen with HEp-2 and serine protease 3 (PR3) were negative. Resected bowel pathology indicated microscopic vasculitis, fibrinoid necrosis of vessel walls, no granulomas and inflammatory cuffing of predominantly mononuclear cells and scatter eosinophils. The differential included eosinophilic granulomatosis with polyangiitis (EGPA), given the symptomatic presentation, pathology, and laboratory testing. The patient was started on methylprednisolone 1g IV for three days, with significant WBC improvement. His symptoms resolved and was discharged on a daily prednisone taper with monthly cyclophosphamide for vasculitis.

Discussion: Our findings outline an unusual presentation of EGPA given the patient’s past medical history and presenting symptoms. EGPA classically begins with allergic rhinitis and asthma, followed by a period of hematologic eosinophilia with tissue infiltrates. The vasculitis phase can be life threatening without prompt recognition and intervention [1,2]. EGPA’s p-ANCA typically targets MPO. p-ANCA is a potent activator of neutrophils which increases inflammation and cell death [3].Initially, the differential included granulomatosis with polyangiitis (GPA) given the positive c-ANCA. Cytoplasmic anti-neutrophil cytoplasmic antibodies (c-ANCAs) primarily target PR3, but PR3 testing was negative in this patient. GPA typically presents with ENT, lung, and kidney involvement. Findings include chronic rhinitis, sinusitis, dyspnea, chest pain, and rapid kidney failure, with the mesangium displaying crescentic glomerulonephritis [4]. A thorough workup with tissue biopsies and identifying the multisystem involvement was essential to get to the proper diagnosis.

Conclusions: Diagnosing EGPA can be complicated by a complex medical history, possibly presenting with generalized pain, stroke, bowel necrosis, and renal failure. A thorough workup, early diagnosis and treatment plan are crucial for a favorable prognosis. Follow-up is critical to determine appropriate response to treatment and complications.