What is eosinophilic esophagitis (EoE)?

Eosinophilic (e-o-sin-o-fil-ik) esophagitis (e-so-fa-gi-tis), referred to as EoE, is a chronic allergic inflammatory disease of the esophagus, the muscular tube that carries food from the throat to the stomach. In the past, it has been referred to as EE.

During an allergic reaction, various cells congregate and cause symptoms like redness, swelling and itchiness. A white blood cell called an eosinophil is one of the types of cells behind an allergic reaction.

Eosinophils are an important part of the immune system and there are always small quantities in the blood and intestine fighting parasites and performing other duties. However, eosinophils cause problems when they appear in high quantities in areas other than the blood and intestine.

If you have seasonal allergies, eosinophils are in your nose; if you have asthma, they are in your lungs; and if you have EoE, they are in your esophagus.

Eosinophilic esophagitis affects children of all ethnicities and family income levels. Children with EoE often have other allergic disorders like asthma, seasonal allergies or eczema.

Thirty years ago, EoE was unknown. Diagnoses have risen dramatically in the past five years. We don't know whether this is because the disease is actually becoming more common, or because it's being recognized much more often. Probably the rising number of cases is due to some combination of the two factors. EoE is still a rare disorder, occurring in an estimated 1 in 1,500 children.

Signs and symptoms of eosinophilic esophagitis

Children experience nausea, regurgitation, vomiting, abdominal pain and a burning feeling similar to acid reflux (heartburn). They may have difficulty swallowing and gag frequently. Often, they feel like something is stuck in their throat. This is called dysphagia. If EoE goes untreated, the esophagus may narrow because of scarring. This is called stricture.

Infants with EoE don't want to breastfeed or take a bottle, and may frequently spit up and arch the back — a sign of pain. Older children eat reluctantly and slowly, don't grow as quickly as expected, develop seemingly irrational aversions to certain foods, and may have trouble sleeping. They may complain of heartburn and dysphagia. Sometimes EoE is diagnosed after a child or teenager comes to the hospital with food in the esophagus that he or she is unable to cough up. This is called food impaction.

EoE shares many symptoms with acid reflux, so a doctor will first prescribe an acid blocker medication or proton pump inhibitor (PPI). These medicines do not help EoE, so if symptoms persist, the doctor will know reflux isn't the cause. It's estimated that up to 10 percent of children with reflux have EoE.

Causes of EoE

We don't know what causes EoE or why it often seems to run in a family. There are several theories, but none have been investigated enough to prove or negate them.

Testing and diagnosis of eosinophilic esophagitis

If you think that your child may have eosinophilic esophagitis, contact your primary care physician. He or she may then refer you either to a pediatric gastroenterologist or allergist for further evaluation.

The only way to diagnose EoE is by a biopsy of the esophagus, performed by a gastroenterologist. The child is sedated and the physician inserts an endoscope into the mouth and through the esophagus, stomach and upper part of the small intestine, where a small sample of tissue is taken.

Sometimes, the gastroenterologist can see signs of EoE in the esophagus, such as "rings" or "white plaques." However, in many cases a child can have EoE and esophageal tissue that appears to be normal. Therefore, it is critical to obtain an esophageal biopsy sample.

Typical allergy tests, such as skin or blood tests that identify immediate allergic reactions, are not usually effective for diagnosis of eosinophilic esophagitis because the allergic reacting involved in EoE is often delayed several days after an allergen is introduced.

Skin patch test is often more insightful, but is not routinely offered by most allergists. Both tests are guidelines on how to introduce foods but like all tests nothing is 100 percent predictive.