Your pathology report for eosinophilic esophagitis

by Jason Wasserman MD PhD FRCPC
July 25, 2025

Eosinophilic esophagitis is a chronic inflammatory condition that affects the esophagus, the muscular tube that carries food from your mouth to your stomach. In this condition, the inner lining of the esophagus becomes inflamed due to the buildup of eosinophils, a type of white blood cell involved in allergic responses. Over time, this inflammation can damage the tissue and interfere with the normal function of the esophagus.

What are the symptoms of eosinophilic esophagitis?

Eosinophilic esophagitis can cause a variety of symptoms. These may include:

  • Difficulty swallowing food, especially hard or dry foods.

  • Food getting stuck in the esophagus after swallowing (known as food impaction).

  • Throat or chest pain.

  • A feeling of tightness or pressure in the chest.

  • Heartburn or symptoms similar to acid reflux (GERD).

  • In children, symptoms may include feeding difficulties, vomiting, or poor weight gain.

If left untreated, long-term inflammation can cause the esophagus to narrow (a condition called stricture), which can make it even more difficult to swallow solid food.

What causes eosinophilic esophagitis?

Eosinophilic esophagitis is believed to be triggered by an allergic reaction, often to specific foods. When the immune system overreacts to these food allergens, it sends eosinophils to the lining of the esophagus. The presence of these immune cells causes inflammation and tissue damage.

Unlike typical food allergies that cause symptoms like hives or anaphylaxis, eosinophilic esophagitis causes more subtle, long-term symptoms that affect the esophagus. The reaction happens as the food passes through the esophagus, even if the food never reaches the stomach.

Who is at risk for developing eosinophilic esophagitis?

Certain factors may increase the risk of developing eosinophilic esophagitis:

  • A personal or family history of allergies, asthma, eczema, or seasonal hay fever.

  • A parent or sibling with eosinophilic esophagitis.

  • A history of non-food allergies or environmental allergens.

  • Gastroesophageal reflux disease (GERD), especially when long-standing or poorly controlled.

GERD may damage the protective lining of the esophagus, making it easier for food allergens to trigger an immune response.

How is eosinophilic esophagitis diagnosed?

The diagnosis of eosinophilic esophagitis requires a procedure called an upper endoscopy with biopsies. During this procedure, your doctor passes a thin, flexible tube with a camera into your esophagus to examine the tissue lining. If eosinophilic esophagitis is suspected, multiple small samples of tissue called biopsies will be taken from different areas of the esophagus.

Because the inflammation in eosinophilic esophagitis can occur in patches, it is important to take biopsies from the upper (proximal), middle, and lower (distal) parts of the esophagus. These samples are then sent to a pathologist, who examines them under a microscope.

What does eosinophilic esophagitis look like under the microscope?

When a pathologist examines the biopsy samples under the microscope, they look for specific signs of inflammation:

  • Intraepithelial eosinophils: A large number of eosinophils are seen in the epithelium, the thin layer of cells lining the inside of the esophagus. This is the key feature of eosinophilic esophagitis.

  • Eosinophilic microabscesses: Small clusters of eosinophils may form, especially in more severe cases.

  • Basal cell hyperplasia: The bottom layer of the epithelium, known as the basal cell layer, becomes thicker as the esophagus tries to repair the damage.

  • Spongiosis: Tiny spaces may form between the cells of the epithelium, a sign of ongoing inflammation.

These changes confirm the diagnosis and help doctors understand the severity of the condition.

How is eosinophilic esophagitis treated?

Treatment usually involves one or more of the following:

  • Dietary changes: Your doctor may recommend an elimination diet to identify and remove trigger foods.

  • Proton pump inhibitors (PPIs): These medications reduce stomach acid and can help reduce inflammation.

  • Topical corticosteroids: These medications are swallowed (not inhaled) to coat the esophagus and reduce inflammation.

  • Endoscopic dilation: In some cases, if the esophagus becomes narrowed, a procedure may be done to gently stretch it and relieve symptoms.

The goal of treatment is to reduce inflammation, relieve symptoms, and prevent long-term damage.

Questions to ask your doctor

  • Do you know what might be triggering this reaction?

  • Will I need to change my diet, and should I see an allergist or dietitian?

  • What treatments do you recommend to manage the inflammation?

  • How will we monitor the condition over time?

  • Could this condition cause long-term damage to my esophagus?

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