Table 2 Definition and classification of eosinophilia [1,2,3] and hypereosinophilic syndrome (HES) [7]

Definition of eosinophilia

 • % eosinophils in the peripheral blood: 3–5%

 and/or

 • AEC: 350–500/μL

Classification of the severity of eosinophilia

Definition of HES

 • AEC: ≥ 1500/μL

 and

 • Clinical manifestations attributable to eosinophilia or tissue HE with blood eosinophilia

Classification of HES

 • Myeloproliferative HE/HES (M-HE/M-HES)

 • Lymphocytic variant HE/HES (L-HE/L-HES)

 • Overlap HES

 • Associated HE/HES

 • Familial HE/HES