Definition: An eosinophil is a type of white blood cell (leucocytes) that is commonly associated with allergic responses or with parasitism.
The eosinophil has a characteristic appearance under the microscope due to the presence of pink staining granules.
Finding eosinophils in tissue suggests allergic disease usually whereas finding increased eosinophil numbers in a blood sample more commonly suggest parasitism.
Pathology
eosinophilic infiltration
eosinophilic disorders
See also
eosinophil development
eosinophil differentiation
eosinophil progenitors
References
Kay AB. The role of eosinophils in the pathogenesis of asthma. Trends Mol Med. 2005 Apr;11(4):148-52. PMID: 15823751