Eosinophile cells have been found both in the vesicles and the blood.
"Essentials of Diseases of the Skin" by Henry Weightman Stelwagon
Mononuclear eosinophil cells ("=eosinophil myelocytes=").
"Histology of the Blood" by Paul Ehrlich
This would explain the role of the eosinophiles in the black-fly lesion.
"Handbook of Medical Entomology" by William Albert Riley
Eosinophils are the principal effector cells involved in the pathogenesis of allergic inflammation.
Eosinophilic Esophagitis, or EoE, is a chronic disease that occurs when eosinophils , a type of white blood cell, cluster in the esophagus and cause inflammation and swelling.
Abstract Eosinophilic granuloma is an uncommon condition that is characterized by unifocal or multifocal osteolytic lesions that often affect the skull.