A 36-Year-Old Woman With a Worsening Cough and Hearing Loss

Nicole Davey-Ranasinghe, MD; Constantine K. Saadeh, MD

Disclosures

September 05, 2019

Suspecting EGPA in patients with peripheral eosinophilia, allergic rhinitis, and asthma is essential. However, confirming the diagnosis can be difficult because vasculitis is not universally clinically evident. The American College of Rheumatology (ACR) has established criteria for the classification of EGPA.[2] However, these classification criteria apply to patients with documented vasculitis. Among patients with EGPA, only 40%-60% have positive ANCA results.

Biopsies are also not always conclusive for granulomas or necrotizing vasculitis and may show less specific changes, such as infiltration of the vessel with eosinophils. Therefore, if EGPA is clinically suspected, further evaluation and work-up are needed to establish the diagnosis. The presence of four or more of the ACR criteria has a sensitivity of 85% and a specificity of 99.7% for the diagnosis of EGPA.[2] The criteria include the following:

  • Asthma

  • > 10% eosinophils on differential

  • Mononeuropathy or polyneuropathy

  • Migratory or transient pulmonary opacities detected radiographically

  • Paranasal sinus abnormality

  • Biopsy containing a blood vessel showing accumulation of eosinophils in extravascular areas

The Lanham criteria require three criteria for a diagnosis of EGPA[3]: asthma, peak peripheral blood eosinophilia > 1500 cells/µL, and systemic vasculitis involving two or more extrapulmonary organs.

Although no laboratory test is specific for EGPA, the presence of myeloperoxidase ANCAs can help raise the clinical likelihood of the diagnosis. In general, evaluation for peripheral eosinophilia with a complete blood cell count including differential is recommended. Inflammatory markers can be elevated or normal. Other laboratory evaluations to evaluate for renal or cardiac involvement may also be considered, if clinically indicated.

In this case, the patient had new-onset chest pain. EKG was performed, and troponin levels were checked. Cardiac manifestations for EGPA can vary; rhythm abnormalities, heart failure, and pericarditis have been reported. Endomyocardial biopsy may be obtained if endomyocarditis is suspected. Cardiac involvement may affect the clinical decision whether to start immunosuppressive therapy. Other noninvasive cardiovascular testing—including ECG, echocardiography, and cardiac MRI with gadolinium—is often part of the evaluation for patients with suspected cardiac involvement due to EGPA.

The differential diagnosis for EGPA is broad. Aspirin-induced respiratory disease; chronic eosinophilic pneumonia; hypereosinophilic syndrome; and other vasculitides, including GPA and microscopic polyangiitis, should all be considered in a patient with suspected EGPA.

In this case, GPA was less likely, on the basis of the patient's history of worsening asthma and lack of necrotic lesions on nasal examination. The presence of myeloperoxidase rather than proteinase-3 ANCA also favors a diagnosis of EGPA. Likewise, the myeloperoxidase antibody is not seen in hypereosinophilic syndrome. Finally, although aspirin-associated respiratory disease can mimic EGPA, the patient reported no significant history of aspirin use.

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