There is a lack of universal consensus for diagnostic criteria.
The American College of Rheumatology (ACR) has established classification criteria for EGPA.
The presence of 4 or more of the 6 criteria produces a sensitivity of 85% and a specificity of 99.7%.
For patients with vasculitis, the presence of asthma and eosinophilia is 90% sensitive and 99% specific for EGPA.
|Classification and Diagnostic Criteria for EGPA|
|Classification Criteria||Diagnostic Criteria|
|American College of Rheumatology (Preferred; Requires 4 of 6)||Lanham (Requires All 3)|
Eosinophilia (>10% total WBC count)
Neuropathy (mono- or polyneuropathy)
Pulmonary infiltrates (migratory or transitory)
Paranasal sinus abnormality (pain, tenderness, or radiologic abnormality) Extravascular eosinophils (in a biopsy containing an artery, arteriole, or venule)
Eosinophilia (>10% WBC count
or >1.5 × 109)
Systemic vasculitis affecting
at least two or more extrapulmonary sites
WBC, White blood cell.
*Classification criteria constitutes a unique set of uniform characteristics among groups of patients for the purpose of further study.
Though not intended for individual-level diagnosis, it is frequently applied for these purposes.
Adapted from Hochberg MC et al: Rheumatology, ed 5, St Louis, 2011, Mosby.