What is an Eosinophil-Associated Disease?
Eosinophils are a type of white blood cell and they play an important part of our immune system. Eosinophils help us fight off certain types of infections, such as parasites. They are named because of the characteristic microscopic stain that gives them a reddish color under a microscope.
Many different problems can cause high numbers of eosinophils in the blood including allergies (food and environmental), certain infections (caused by parasites), eosinophil-associated gastrointestinal disorders, leukemia, and other problems
Typically, eosinophils make up less than 5% of circulating white blood cells in healthy individuals and can vary over time in healthy individuals. When a person has elevated numbers of eosinophils in their digestive system, tissues, organs, and/or bloodstream, without a known cause, he or she may have an eosinophil-associated disease.
The diagnosis depends on where the eosinophils are found:
- Eosinophilic Cystitis: bladder
- Eosinophilic Fasciitis: connective tissue
- Eosinophilic Gastrointestinal Disorders (an umbrella term for subsets in the GI tract; international consensus granularly identifies areas of the GI tract that are affected):
- Eosinophilic Esophagitis (EoE) = esophagus
- Eosinophilic Colitis (EoC) = colon
- Eosinophilic Duodenitis (EoD) = duodenum
- Eosinophilic Enteritis (EoN) = small bowel
- Eosinophilic Gastritis (EoG) = stomach
- Eosinophilic Jejunitis (EoJ) = jejunum
- Eosinophilic Ileitis (EoI) = ileum
- Eosinophilic Granulomatosis with Polyangiitis, aka Churg-Strauss Syndrome: lungs, sinuses, heart, various organ systems
- Eosinophilic Pneumonia: lungs
- Hypereosinophilic Syndrome: blood and any organ
Photo Credit: Eosinophil, Courtesy of Dr. Margaret Collins
Eosinophil-associated diseases are chronic and require long term management. The symptoms may be debilitating and often lead to missed time at school and work, and may greatly impact a patient’s quality of life.
Learn more about each of the subsets of eosinophil-associated diseases, including diagnosis, symptoms, and management, by browsing through our website.
© American Partnership for Eosinophilic Disorders (APFED) 2013-2022 All rights reserved. Content may not be reproduced in whole or in part without express written consent from APFED. Authors: Wendy Book, MD; Margaret Collins MD