Case Presentation: A 27-year-old white male with adult-onset asthma and recurrent pneumonia presented to a rural hospital with a one month history of ascending lower extremity numbness. He also reported fever, fatigue, night sweats, and a twenty-pound weight loss over three weeks. Initial workup revealed leukocytosis and eosinophilia, prompting transfer to our facility for further evaluation by hematology and infectious disease services.
Physical examination was significant for fever of 101.5°F, diffuse expiratory wheezing, and diminished sensation in the lower extremities. Laboratory analysis showed elevations in white blood cell count (22,000/μL), absolute eosinophil count (13,500/μL), inflammatory markers (ESR of 36 mm/hr, CRP of 9.25 mg/dL), and IgE (224 mg/dL). Serological analysis revealed an elevated rheumatoid factor (22.4 IU/mL) as well as a positive antinuclear antibody. While p-ANCA was found to be positive (1:40), c-ANCA was negative. Leukemia/lymphoma immunophenotyping by flow cytometry was negative. The patient’s blood, sputum, and urine cultures had no growth. His respiratory viral panel and QuantiFERON®-TB Gold were negative. Chest CT exhibited bilateral scattered ground-glass opacities. MRI of the brain showed diffuse inflammation of the sinuses. Transthoracic echocardiogram was normal. The patient reported worsening paresthesias, prompting right sural nerve biopsy which showed severe neuropathy with primary axonal degeneration.
The patient met five out of the six criteria for the classification of eosinophilic granulomatosis with polyangiitis (EGPA) established by the American College of Rheumatology: asthma, >10% eosinophilia, polyneuropathy, transient pulmonary opacities on radiographs, and paranasal sinus abnormality. Meeting at least four of the six criteria provides a sensitivity of 85% and specificity of 99.7% for the diagnosis of EGPA. Treatment was initiated with prednisone, which was later tapered with the addition of azathioprine. At six-month follow up, he had downtrending eosinophilia as well as improvement of cough, dyspnea, and paresthesias.
Discussion: EGPA is a rare form of autoimmune vasculitis, with a reported annual incidence of 0.5-6.8 new cases per million. The prodromal phase is an allergic phase where patients develop adult-onset asthma or allergic rhinitis. The eosinophilic phase involves peripheral eosinophilia and involvement of multiple organ systems, such as the migratory pulmonary infiltrates in our patient. The vasculitic phase consists of constitutional symptoms (such as the fever, fatigue, and weight loss our patient exhibited) and peripheral neuropathy. Prompt recognition of this disease process, in the pre-vasculitic phase, can result in earlier treatment thus reducing morbidity for our patients.
Conclusions: EGPA is among the most rare of vasculitides and can present with a wide array of presenting signs and symptoms, making this disease a diagnostic puzzle. As demonstrated in this case, diagnosis often requires the involvement of multiple specialists in the inpatient setting. Hospitalists should maintain a high degree of suspicion for EGPA when patients present with adult-onset asthma, particularly in the setting of eosinophilia and polyneuropathy.