Eosinophilic esophagitis (EoE): the allergy connection

Food gets stuck in your throat. Not in a choking, call-911 way, but in a "this piece of chicken will not go down and you have to drink water to push it through" way. Or you avoid eating steak because you know it will lodge. Or you eat slowly and chew everything to mush because you have learned the hard way what happens when you do not. For years, you might have assumed this was just how you eat. Doctors might have told you to chew more carefully or that you eat too fast. But difficulty swallowing solid food, especially in a young adult or child who also has allergies, is a hallmark symptom of eosinophilic esophagitis, a condition where allergic immune cells accumulate in the esophagus and cause inflammation, swelling, and eventually scarring that narrows the passage food has to travel through.

Key takeaways

• EoE is a chronic immune condition where eosinophils (allergic white blood cells) accumulate in the esophagus, causing inflammation that leads to difficulty swallowing and food impaction
• It is increasingly recognized as an allergic condition driven by specific food triggers, most commonly milk, wheat, eggs, soy, nuts, and seafood
• Diagnosis requires endoscopy with esophageal biopsies showing elevated eosinophil counts, and treatment includes dietary elimination of trigger foods and swallowed topical corticosteroids

What EoE is

Eosinophilic esophagitis (EoE, pronounced "ee-oh-ee") is a chronic, immune-mediated inflammatory disease of the esophagus. The defining feature is the accumulation of eosinophils, a type of white blood cell associated with allergic responses, in the tissue lining the esophagus. In a healthy esophagus, eosinophils are not normally present. When they accumulate in significant numbers (the diagnostic threshold is 15 or more eosinophils per high-power field on biopsy), they release inflammatory chemicals that damage the esophageal lining, cause the tissue to swell, and over time lead to fibrosis (scarring) that stiffens and narrows the esophageal tube.

EoE was first described as a distinct condition in the early 1990s, and its recognition has grown rapidly since then. It is now understood to be one of the most common causes of difficulty swallowing in children and young adults, and one of the most common reasons for food impaction (food getting completely stuck in the esophagus and requiring emergency removal). The prevalence has been increasing over the past two decades, though it is debated whether this reflects a true increase in the disease or better recognition and more frequent endoscopy.

The allergy connection

EoE is increasingly understood as an allergic disease. The eosinophilic inflammation in the esophagus is driven by the same Th2 immune pathway that drives other allergic conditions: the same interleukins (IL-4, IL-5, IL-13), the same eosinophil activation, and the same IgE and non-IgE mediated immune responses that characterize atopic dermatitis, allergic rhinitis, and allergic asthma. About 50 to 80 percent of EoE patients have concurrent allergic conditions (food allergies, environmental allergies, asthma, eczema), and EoE is now considered part of the broader atopic disease spectrum.

The trigger for EoE is most commonly a specific food allergen. When the patient eats the trigger food, the immune system mounts an eosinophilic response specifically in the esophagus. The eosinophils migrate into the esophageal tissue, release their inflammatory granules, and cause the tissue damage that produces symptoms. Removing the trigger food from the diet allows the eosinophils to clear and the inflammation to resolve. Reintroducing the food causes the eosinophils to return. This food-specific, reproducible pattern is the strongest evidence for the allergic nature of the disease.

Environmental allergens may also play a role. Some patients notice that their EoE symptoms worsen during pollen season, suggesting that airborne allergens can contribute to esophageal eosinophilia through swallowed pollen or systemic immune activation. This seasonal variation is an area of active research and may explain why some patients have fluctuating symptom severity even when their diet does not change.

Symptoms of EoE

Symptoms vary by age and often evolve over the course of the disease.

In adults and older children

Dysphagia (difficulty swallowing) is the most common presenting symptom in adults and adolescents. Patients describe food "sticking" or "getting hung up" in the chest, usually with solid foods rather than liquids. Meat, bread, and rice are the most commonly cited problem foods because of their texture. Some patients learn to compensate by eating slowly, chewing excessively, cutting food into tiny pieces, and drinking fluids with every bite to wash food down. These behavioral adaptations can mask the severity of the problem for years.

Food impaction is the most dramatic manifestation. A bolus of food becomes lodged in the esophagus and cannot pass. The patient cannot swallow, may drool, and experiences intense chest pain. Food impaction often requires emergency endoscopy to remove the obstruction. For some patients, food impaction is the event that leads to diagnosis after years of unrecognized symptoms.

Chest pain that is not cardiac in origin is another EoE symptom. The inflammation and muscle spasm in the esophagus can produce a squeezing or burning sensation behind the breastbone that mimics heart-related chest pain. Some patients undergo cardiac evaluation before the esophageal cause is identified.

Heartburn and reflux-like symptoms overlap with gastroesophageal reflux disease (GERD), which can complicate diagnosis. Some patients are initially treated for GERD with acid-suppressing medication and only investigated for EoE when they do not respond to reflux treatment.

In young children

Young children with EoE often present differently because they cannot articulate swallowing difficulty. Instead, the clues are feeding difficulties (refusal to eat certain textures, slow eating, gagging), vomiting, abdominal pain, failure to thrive (poor weight gain), and food aversion. A child who suddenly becomes "picky" about textures or who regresses from eating solids to preferring liquids may have undiagnosed EoE. The overlap with general childhood feeding issues makes diagnosis challenging without a high index of suspicion.

Diagnosis

EoE cannot be diagnosed without endoscopy and biopsy. There is no blood test, imaging study, or symptom pattern that is sufficient alone. The endoscope is passed through the mouth into the esophagus, and the gastroenterologist looks for visual features suggestive of EoE: rings (concentric ridges that give the esophagus a "ringed" or "feline" appearance), linear furrows (vertical grooves in the lining), white plaques (clusters of eosinophils visible on the surface), edema (swelling that makes the lining look pale and featureless), and strictures (narrowing from chronic scarring).

Biopsies are taken from multiple levels of the esophagus (typically proximal and distal) and examined under a microscope. The pathologist counts eosinophils per high-power field. A count of 15 or more per high-power field, in the proper clinical context and after excluding other causes of esophageal eosinophilia (primarily GERD), establishes the diagnosis. Multiple biopsies are important because the eosinophilic infiltrate can be patchy, and sampling only one area may miss the affected tissue.

Identifying food triggers

The most common food triggers for EoE are cow's milk, wheat, eggs, soy, tree nuts and peanuts, and fish and shellfish. Cow's milk is the single most frequently identified trigger across studies, responsible for triggering EoE in roughly 50 to 60 percent of patients. Wheat is second, followed by eggs and soy. Some patients have a single food trigger. Others have two or three. Rarely, patients have triggers outside the common list.

Identifying the specific trigger is the goal of dietary therapy, but the path to identification is less straightforward than with typical food allergies. Standard allergy testing (skin prick tests and blood IgE) is not reliable for predicting EoE food triggers. Many patients with EoE have positive skin tests to foods that do not actually trigger their esophageal disease, and some patients have negative tests to foods that are confirmed triggers. This is because EoE involves both IgE-mediated and non-IgE-mediated immune mechanisms, and standard allergy tests only detect the IgE component.

Allergy testing is still worth performing because it provides some guidance and can identify coexisting IgE-mediated food allergies that need separate management. But the definitive identification of EoE triggers requires dietary elimination followed by endoscopic reassessment.

Empiric elimination diet

The most widely used approach is the six-food elimination diet (SFED), where the six most common trigger food groups (milk, wheat, egg, soy, nuts, and fish/shellfish) are removed from the diet simultaneously. After six to eight weeks of elimination, the patient undergoes repeat endoscopy with biopsies. If the eosinophils have cleared (count drops below 15 per high-power field), the elimination was successful, confirming that at least one of the six food groups is a trigger.

Foods are then reintroduced one at a time, each for six to eight weeks, followed by endoscopy. When a reintroduced food causes the eosinophils to return, that food is identified as a trigger. The process is lengthy (each reintroduction cycle requires six to eight weeks plus an endoscopy), but it is the most reliable method for identifying specific triggers. Some centers now start with a two-food elimination (milk and wheat, the two most common triggers) to reduce the number of endoscopies needed, moving to broader elimination only if the initial two-food removal does not achieve remission.

Targeted elimination based on allergy testing

An alternative approach uses allergy test results to guide which foods to eliminate first. If skin testing shows strong sensitization to milk and wheat, those foods are eliminated and the response is assessed endoscopically. This approach is less standardized than empiric elimination and may miss non-IgE-mediated triggers, but it can reduce the number of foods eliminated simultaneously and the number of endoscopies needed if the test results happen to identify the actual trigger. We use a combination of allergy testing and clinical judgment to guide the initial elimination strategy for each patient.

Treatment options

Dietary elimination

Once a trigger food is identified, long-term avoidance of that food is the most targeted treatment. If milk is your trigger, removing milk and milk-containing products from your diet allows the esophageal inflammation to resolve and stay in remission as long as the trigger is avoided. Dietary elimination requires careful label reading (trigger foods, especially milk, are present in many processed products under various names), nutritional planning (to ensure adequate calcium and protein if dairy is removed), and periodic monitoring with endoscopy to confirm ongoing remission.

For patients whose trigger is a single, easily identified food, dietary elimination can provide complete disease control without medication. For patients with multiple triggers or triggers that are difficult to avoid (milk is in an enormous number of processed foods), the practical burden of dietary elimination may be significant, and medication-based treatment may be preferred or used in combination.

Swallowed topical corticosteroids

This is the primary pharmacological treatment for EoE. Fluticasone propionate (a metered-dose inhaler, but instead of inhaling it into the lungs, the patient sprays it into their mouth and swallows it without inhaling) or budesonide (mixed with a thickening agent like Splenda or honey to create a slurry that coats the esophagus when swallowed) delivers corticosteroid directly to the esophageal lining. The steroid suppresses the eosinophilic inflammation locally.

Swallowed topical steroids are effective in inducing remission (clearing eosinophils from the esophagus) in approximately 50 to 70 percent of patients. They are used for both acute treatment (inducing remission) and maintenance therapy (preventing relapse). Side effects are generally mild because the steroid acts locally rather than systemically, though esophageal candidiasis (yeast infection) is a known risk and patients should rinse their mouth after taking the medication.

Dupixent (dupilumab) was FDA-approved for EoE in 2022, making it the first biologic therapy specifically approved for this condition. It targets the IL-4 and IL-13 immune pathways that drive eosinophilic inflammation. For patients who do not respond to dietary elimination or topical steroids, or who prefer a treatment that does not require dietary restriction, dupilumab offers a new option.

Proton pump inhibitors

Proton pump inhibitors (PPIs) like omeprazole and lansoprazole have been found to induce histological remission in a subset of EoE patients (termed "PPI-responsive esophageal eosinophilia," now considered part of the EoE spectrum). PPIs have anti-inflammatory effects beyond acid suppression that may explain their benefit. A trial of PPI therapy is often included in the initial management algorithm, and patients who respond can be maintained on PPI without needing steroids or dietary elimination.

Esophageal dilation

For patients with established strictures (narrowing from chronic scarring), esophageal dilation is a mechanical procedure performed during endoscopy. A balloon or graduated dilators are used to stretch the narrowed segment, improving the diameter of the esophageal lumen and reducing dysphagia. Dilation does not treat the underlying inflammation (medication or dietary treatment is still needed for that), but it addresses the structural consequence of years of untreated disease. The procedure is safe in experienced hands and often provides immediate improvement in swallowing.

The role of the allergist in EoE management

EoE sits at the intersection of gastroenterology and allergy. The gastroenterologist performs the endoscopies, takes biopsies, and manages esophageal complications. The allergist contributes allergy testing to help guide dietary elimination, manages coexisting allergic conditions (many EoE patients also have allergic rhinitis, asthma, or eczema), and provides expertise on food allergy management including label reading, nutritional counseling referrals, and emergency preparedness if coexisting IgE-mediated food allergies are present.

For patients in Central Texas with suspected or confirmed EoE, we work collaboratively with local gastroenterologists to provide the allergy component of care. The allergy evaluation includes testing for environmental and food allergens, counseling on elimination diets, monitoring for nutritional adequacy during dietary restriction, and ongoing management of the atopic conditions that often accompany EoE.

Living with EoE

EoE is a chronic condition that requires ongoing management. It does not resolve on its own, and untreated disease leads to progressive fibrosis and worsening stricture formation. The good news is that with appropriate treatment (dietary elimination, swallowed steroids, biologics, or a combination), most patients achieve good symptom control and can eat comfortably.

The adjustment to dietary elimination, when needed, can be significant, especially for patients whose trigger is a ubiquitous ingredient like milk or wheat. Support from a dietitian experienced with food allergy and EoE diets is valuable for maintaining nutritional balance and finding satisfying alternatives. Patient support communities and resources (including APFED, the American Partnership for Eosinophilic Disorders) provide practical guidance and connection with others managing the same condition.

If you or your child has difficulty swallowing solid food, gets food stuck regularly, or has been treated for reflux without improvement, EoE should be considered. It is underdiagnosed, partly because patients adapt to their symptoms (eating slowly, avoiding certain textures, drinking large amounts of water with meals) and partly because the diagnosis requires endoscopy rather than a simple blood test. But once identified, it is very treatable, and the improvement in quality of life from being able to eat normally again is substantial.

EoE awareness and advocacy

EoE is still underdiagnosed, partly because patients adapt to their symptoms and partly because many physicians were not trained on the condition (its recognition as a distinct disease is only about 30 years old). Patients who have been struggling with food getting stuck, eating slowly, or avoiding certain textures for years may not realize these are symptoms of a treatable medical condition rather than just the way they eat.

If you recognize yourself in the symptom descriptions in this article, bring it up with your doctor or contact an allergist or gastroenterologist directly. EoE is diagnosed through a straightforward (though invasive) test (endoscopy with biopsies), and the treatments available today, from dietary elimination to swallowed steroids to dupilumab, can dramatically improve swallowing function and food enjoyment. Living with undiagnosed EoE means ongoing esophageal damage, progressive stricture formation, and increasing risk of food impaction emergencies. Getting diagnosed and treated stops that progression and often restores normal eating.