EoE stands for eosinophilic esophagitis, a chronic allergic condition where a type of white blood cell called an eosinophil builds up in the lining of the esophagus, the tube that carries food from your mouth to your stomach. It affects roughly 142 out of every 100,000 people in the United States, which translates to nearly half a million Americans living with the condition. Once considered rare, EoE is now recognized as one of the leading causes of swallowing difficulty and food getting stuck in the throat.
What Happens Inside the Esophagus
Eosinophils are immune cells that normally help fight parasites and infections. In EoE, the immune system mistakenly reacts to certain food proteins as if they were threats. This triggers an allergic chain reaction: cells in the esophageal lining release signaling molecules that recruit eosinophils and other inflammatory cells into the tissue. Once there, eosinophils release toxic proteins that damage the esophageal lining, widen the gaps between cells, and cause swelling.
Over time, this repeated inflammation reshapes the esophagus itself. The tissue thickens, stiffens, and can develop scar tissue, a process called fibrosis. A healthy esophagus is flexible and stretches easily when food passes through. An esophagus affected by EoE gradually loses that flexibility, narrows, and becomes prone to food getting stuck. This remodeling is not just theoretical: in one large study tracking newly diagnosed patients over two decades, the percentage who had visible narrowing (strictures) at diagnosis rose from 20% in the early 2000s to 41% between 2016 and 2020, largely because many people go years before getting a correct diagnosis.
Symptoms in Adults vs. Children
EoE looks different depending on age. Adults most commonly experience dysphagia, the sensation that food is sticking or moving slowly down the chest. Some adults first learn they have EoE after a piece of meat or bread becomes fully lodged in the esophagus (a food impaction), requiring an emergency room visit to have it removed. A smaller group of adults present mainly with chest pain, likely caused by esophageal spasms.
Children are harder to pin down. Younger kids often have symptoms that mimic acid reflux: vomiting, nausea, heartburn, and belly pain. Toddlers and infants may simply refuse food or eat very slowly without being able to explain why. A key red flag in children is reflux-like symptoms that don’t improve with standard acid-reducing medications. If antacid therapy isn’t working, EoE is a strong possibility.
How EoE Is Diagnosed
There is no blood test or imaging scan that confirms EoE. Diagnosis requires an upper endoscopy, a procedure where a thin, flexible camera is passed down the throat to examine the esophagus and collect small tissue samples (biopsies). Three criteria must be met for a diagnosis:
- Symptoms of esophageal trouble, such as difficulty swallowing, food impaction, or reflux-like complaints that don’t respond to acid therapy.
- At least 15 eosinophils per high-power microscope field in at least one biopsy sample. A healthy esophagus has essentially zero eosinophils, so this threshold is a clear marker.
- Other causes ruled out. Conditions like acid reflux, infections, and other inflammatory diseases can also draw eosinophils into the esophagus, so those need to be excluded first.
During the endoscopy, doctors look for a set of five characteristic signs: swelling of the lining (edema), circular ridges that give the esophagus a ringed appearance, white spots or patches (exudates), vertical grooves running along the walls (furrows), and narrowing from scar tissue (strictures). Not every patient has all five, but the combination helps gauge severity.
What Causes It
EoE is driven by an allergic immune response to food. The six most common trigger foods are cow’s milk, eggs, wheat, soy, fish, and tree nuts. Milk is by far the most frequent single trigger. Environmental allergens like pollen may also play a role, and some patients notice their symptoms flare during allergy season.
There is a genetic component. EoE runs in families, and researchers have identified several genes involved in maintaining the esophageal barrier that are disrupted in people with the condition. Most patients have a personal or family history of other allergic conditions like asthma, eczema, or hay fever, reinforcing the connection to the broader allergic disease spectrum.
Treatment: Diet-Based Approaches
Because specific foods drive the inflammation, eliminating those foods can put EoE into remission without any medication. The traditional approach, the six-food elimination diet, removes milk, eggs, wheat, soy, fish, and nuts simultaneously. This works, but it is difficult to maintain and requires repeated endoscopies to add foods back one at a time to identify the actual culprit.
A landmark NIH-funded trial involving 129 adults compared the six-food approach head-to-head against simply eliminating animal milk alone. After six weeks, 40% of patients on the milk-only diet achieved remission compared to 34% on the six-food diet, a difference that was not statistically significant. This was a meaningful finding: for a substantial portion of patients, removing just dairy is enough. Many gastroenterologists now start with milk elimination and escalate only if that doesn’t work, sparing patients months of restrictive eating.
Treatment: Medications
The most established medical treatment involves swallowing topical steroids, the same anti-inflammatory medications used in asthma inhalers, but delivered so they coat the esophagus instead of reaching the lungs. The medication comes as a thick liquid or a tablet that dissolves on the tongue and is then swallowed. After taking it, you avoid eating or drinking for at least 30 minutes so the medication stays in contact with the esophageal lining. An initial treatment course typically lasts 6 to 12 weeks to bring inflammation under control, and many patients need ongoing maintenance therapy to prevent relapse.
For patients who don’t respond to steroids or elimination diets, a biologic medication called dupilumab (brand name Dupixent) is FDA-approved for EoE in adults and children age 1 and older. It works by blocking a key immune signaling pathway that drives the allergic response. It’s given as an injection, similar to how it’s used for other allergic conditions like eczema and asthma.
Esophageal Dilation
When scarring has already narrowed the esophagus, stretching (dilation) during an endoscopy can widen the passage and improve swallowing. This doesn’t treat the underlying inflammation but addresses the structural damage. Dilation in EoE was once thought to carry a high risk of tearing the esophagus, but studies have shown the perforation rate is comparable to dilation for other conditions. In one review of EoE-related esophageal perforations, none occurred after dilation. The perforations that did happen were almost all caused by food getting stuck in patients who hadn’t yet been diagnosed or weren’t being treated.
What Happens Without Treatment
EoE is not life-threatening, but it is progressive. Left untreated, the chronic inflammation gradually converts a flexible esophagus into a stiff, narrowed tube. The longer the disease goes unmanaged, the more likely strictures become. Food impactions can become more frequent and more dangerous, sometimes requiring emergency intervention. Treatment, whether through diet, medication, or both, can halt this remodeling process and, in many cases, reverse some of the damage, making early diagnosis and consistent management important for long-term outcomes.