An absolute eosinophil count is a blood test that measures the number of white blood cells called eosinophils. Eosinophils become active when you have certain allergic diseases, infections, and other medical conditions.
This test may help diagnose:
1) Acute hypereosinophilic syndrome (a rare, but sometimes fatal leukemia-like condition)
2) An allergic reaction (can also reveal how severe the reaction is)
3) Early stages of Cushing disease
4) Infection by a parasite
Normal eosinophil count is less than 500 cells per microliter (cells/mcL).
