What is an eosinophilic disorder?
Eosinophilic disorders occur when
eosinophils, a type of white blood cell, are found in above-normal amounts in various parts of the body.
Chronic Inflammation Can Occur
Eosinophils have historically been important to the immune system because they help us fight off certain types of infections, generally tropical parasite infections. Eosinophils release a variety of toxins to kill the foreign substance. When a person has an eosinophilic disorder, their body produces too many eosinophils and chronic inflammation can occur. Elevated levels of eosinophils can be caused by food an environmental allergies, certain infections caused by parasites, eosinophil associated gastrointestinal disorders, leukemia, and other problems. This can ultimately result in tissue damage.
Elevated Levels of Eosinophis Result in a Number of Rare Diseases
Elevated levels of eosinophils can be found in many different parts of the body and result in a number of rare diseases such as:
Eosinophilic Esophagitis (EoE) - A disease characterized by elevated levels of eosinophils in the esophagus (the tube connecting the mouth to the stomach). These high levels of eosinophils generally cannot be adequately controlled by acid blocking medicines. People who suffer from EoE often have allergic diseases such as rhinitis (nasal allergies), asthma, and/or eczema. EoE can often be aggravated by food allergy. Patients with a component of food allergy can improve their symptoms by eliminating specific food proteins from their diet.
Eosinophilic Gastritis - A disease characterized by elevated levels of eosinophils in the stomach.
Eosinophilic Enteritis - A disease characterized by elevated levels of eosinophils in the small intestine.
Eosinophilic Colitis - A disease characterized by elevated levels of eosinophils in the large intestine (colon).
Hypereosinophilic Syndrome - A disease characterized by a high blood and specific organ eosinophilia that can affect any organ in the body. Organ tissue damage can occur.
What are the symptoms of EoE?
Common Symptoms of EoE:
- Reflux that does not respond to usual therapy (examples include medicines which stop acid production in the stomach)
- Dysphagia (difficulty swallowing)
- Food impactions (food gets stuck in the esophagus)
- Nausea and Vomiting
- In children, failure to thrive (poor growth, malnutrition, or weight loss) and poor appetite
- Abdominal or chest pain
- Feeding refusal/intolerance or poor appetite
- Difficulty sleeping
How is EoE diagnosed?
The only way to definitively diagnose EoE is through
endoscopy with biopsies. During an upper endoscopy, the gastroenterologist looks at the esophagus, stomach, and duodenum (first part of the small bowel) through an endoscope (small tube inserted through the mouth) and takes multiple biopsies (small tissue samples) which a pathologist reviews under a microscope.
What happens after the diagnosis?
Once the diagnosis of EoE is confirmed, a patient is typically referred to an allergist for food allergy testing to help guide treatment. Skin prick testing to different foods is the most common type of allergy testing.
The allergist may do testing for immediate sensitivity (allergy), such as
blood testing (RAST or Immunocap) or
skin prick testing. A reaction to food does not always results in immediate hypersensitivity (IgE-mediated). A food can be consumed with no obvious reaction to it, but over a period of days to weeks the eosinophils triggered by the food will cause inflammation and injury to the esophagus. Due to this, food logs are often not an effective way to identify offending food.
Patch testing is often used to look for delayed food reactions.
Skin Prick Testing
Skin prick testing is for IgE-mediated reactions (immediate hypersensitivity). Skin prick testing involves scratching small amounts of pure food or environmental allergens into the skin. A bump and redness greater than the negative control indicates a positive test. Both a positive control and negative control are used.