Eosinophilic esophagitis (abbreviated EoE) is a condition characterized by chronic inflammation of the esophagus.
Eosinophilic esophagitis is a disease that has gained increasing attention in the medical world over the past 20 years. The term “eosinophilic esophagitis” (abbreviated EoE) reflects chronic inflammation (“-itis”) of the esophagus with an increased accumulation of a certain type of inflammatory cells called eosinophils in its mucosa. Eosinophils are a subgroup of white blood cells (leukocytes) that usually fight infections but can also cause inflammation.
The specific causes of this chronic inflammation of the esophagus remain unknown. The disease is thought to be primarily caused by an allergic reaction to certain foods, although other airborne allergens (substances that induce allergies) can also be triggers for inflammation. People with EoE often have other allergic conditions like asthma or hay fever. Finally, genetic factors also appear to play some role in causing the disease.
No specific figures are available on the incidence of eosinophilic esophagitis in Germany. It is estimated that about 29 out of 100,000 adults in Europe suffer from EoE, although there are large variations between different regions. The disease is most common in developed countries.
Eosinophilic esophagitis can start at any age. However, men are three times as likely to have the condition than women, and the disease most commonly begins between the ages of 30 and 50.
The main symptoms reported by people with EoE are difficulty swallowing (dysphagia), painful swallowing (odynophagia), heartburn, and even a feeling of choking/gagging. In some cases, bites of food can become stuck in the throat, block the esophagus (food impaction) and need to be removed endoscopically.
People with EoE have difficulty eating solid, high-fiber, or dry foods. They typically chew their food for a long time, which means they often take longer to finish their meals than healthy people. To make swallowing easier, they drink a lot of liquids while eating. They prefer foods that are easier to swallow, pureed foods, or liquid foods. Many people with EoE avoid restaurants because they are afraid that their problems with swallowing might cause food to get stuck in their throat or that they may need to vomit.
Even though these symptoms can greatly impact quality of life, many people with EoE are not even aware that they have the condition. Instead, they have simply become used to these issues and have developed coping mechanisms.
In children, EoE is often identified indirectly through a loss of appetite, a refusal to eat, choking, vomiting, or poor growth.
If left untreated, complications of eosinophilic esophagitis can develop over many years. Chronic inflammation can cause the tissue in the esophagus to gradually change, which poses the risk that the esophagus will become narrower (stenosis) or constrict (strictures) due to the formation of scar tissue. These complications can make swallowing even more difficult than it already was.
Complications can also occur during the acute stage of the disease when bites of food become stuck in the esophagus. When this happens, the food may need to be removed with an emergency endoscopy.
People with EoE often also have other allergies, such as hay fever, allergic asthma, eczema, or food allergies.
Nearly any patient who reports recurring symptoms while swallowing can be suspected of having eosinophilic esophagitis. These patients should undergo further tests with a gastroenterologist.
To help clarify and confirm the suspected diagnosis, the doctor will need to collect information about the patient’s medical history (anamnesis). This will include questions about current symptoms, whether similar symptoms occur frequently or only occasionally, and when the patient first noticed them.
The patient will be asked whether he or she has any known food allergies or other allergies and whether any of the patient’s relatives also have difficulty swallowing.
The doctor will also need to learn about the patient’s eating habits. Specific questions include whether the patient needs an especially long time to eat, chews his or her food for a long time, only eats small bites, drinks lots of liquids, or tends to avoid solid foods.
In order to reach a diagnosis of eosinophilic esophagitis, the gastroenterologist must view the esophagus using a procedure called upper endoscopy. Patients with EoE usually have signs of inflammation and potentially already scar tissue resulting from chronic inflammation that can be identified just by looking at the esophagus by upper endoscopy. The signs of inflammation may include redness, swelling and thickening of the mucosa, and/or furrows and narrowing.
However, the diagnosis of EoE can only be confirmed by collecting tissue samples (biopsies) during the upper endoscopy and viewing them under a microscope to see whether there are increased numbers of eosinophils in the mucosa of the esophagus.
Although there is currently no cure for eosinophilic esophagitis, the symptoms of chronic inflammation of the esophagus can be sustainably managed.
The goal of using medications to treat EoE is to improve patients’ quality of life by providing long-term symptom relief, which should also help prevent the disease from progressing. There are currently three potential drugs that can be used to treat EoE:
- Topical corticosteroids with anti-inflammatory effects, which are recommended as first-line therapy by the relevant German medical society
- Proton pump inhibitors (PPIs), which are acid blockers that lower the production of stomach acid and which are not officially approved for the treatment of EoE
Regulatory authorities in Europe have approved an immunomodulatory treatment for adults and children above 12 years of age who are inadequately controlled by conventional treatment, cannot tolerate it or for whom it is not an option. Country-specific regulations might apply.
According to the medical guidelines in several European countries like for example in Germany or the UK, patients with acute EoE should take topical corticosteroids for 6 weeks at first, although treatment can also be extended to 12 weeks if symptoms persist. After this period, an endoscopy of the esophagus should be performed to evaluate the treatment outcome. Inflammation often flares up once treatment is stopped, leading to new symptoms, thus the drug should be taken continuously, usually at a lower dose. Continuous long-term therapy and regular endoscopy check-ups with collection of tissue biopsies are important: if left untreated, the disease progresses, and the esophagus may become increasingly narrow due to scar tissue.
Because eosinophilic esophagitis appears to be closely linked to food allergies, patients may be able to stop the inflammation by avoiding foods they know they are allergic to. There is evidence that animal milk and dairy products, wheat/gluten, soy/legumes, eggs, nuts, as well as fish and shellfish may be very common triggers or causes of eosinophilic esophagitis. This opens up the possibility of dietary therapy by leaving these foods completely out of one’s diet. There are different types of diets that leave out either two (dairy and wheat/gluten), four (dairy, wheat/gluten, eggs, soy/legumes), or even all six food groups from the menu. This type of therapy should be carried out with the support of a nutrition specialist whenever possible. Depending on how strict the diet is, these therapies can come with drastic changes to daily life and quality of life.
It is also possible to follow an elemental diet using amino acid-based formulas that leaves out all normal foods entirely. While this type of diet has shown very good results, it is very difficult to maintain as long-term therapy due to the major burden it places on daily life.
Strict dietary therapy is therefore especially recommended during phases with acute inflammation of the esophagus, but is rarely practical for longer periods of time.
Another option for treating eosinophilic esophagitis is widening (dilation) of the esophagus during an upper endoscopy. Dilation is beneficial when scar tissue has already started to narrow the esophagus. During this procedure, the stenosis and strictures that reduce the diameter of the esophagus are mechanically stretched.
However, this procedure does not treat the inflammation that causes the constriction, and the esophagus usually begins to narrow again in the absence of targeted medication or dietary therapy, requiring repeated dilation.
Outlook and prognosis
The outlook and prognosis for eosinophilic esophagitis depend on how early effective treatment is started and how consistently inflammation is suppressed. This is because chronic inflammation leads to the formation of scar tissue, which eventually causes narrowing of the esophagus. Late treatment also increases the risk of potential complications like blockage of the esophagus by solid food (food impaction). Repeated emergency endoscopies to remove food blocking the esophagus should be avoided by any means as these always have a certain risk for injuries of the esophagus.