A little-known immune condition is being mistaken for food allergies

A chronic inflammatory condition is becoming more common, and its symptoms can be mistaken for a severe allergic reaction. Eosinophilic oesophagitis (EoE) is a rare condition where a type of white blood cells, known as eosinophils, builds up in the oesophagus. It is thought to affect around 40 in every 100,000 people. Eosinophils play an important role in the body’s immune system, helping to destroy invader parasites and pathogens before they cause harm to other cells. They also have a role in regulating inflammation, but can cause tissue damage when it becomes excessive, such as in EoE. Advertisement EoE can cause symptoms similar to that of anaphylaxis – a severe food allergy reaction – such as swelling, problems swallowing, drooling and the sensation of food stuck in the throat. Two new studies on EoE have been presented at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting in Phoenix, Arizona, this week. In the first study, Talal Nsouli at Georgetown University in Washington DC and his colleagues investigated 29 adults who were referred to a specialist because doctors suspected they had anaphylaxis. Patients reported repeated episodes of chest pain, drooling and problems swallowing after consuming certain foods. On average, each person went to hospital three times, and received at least one dose of adrenaline, the treatment for anaphylaxis. However, none of the participants tested positive for Ig-E mediated anaphylaxis, a specific type of rapid, life-threatening reaction triggered by the immune system. These patients were then tested for EoE with samples taken from the lining of the oesophagus, which came back positive for the condition. “Not every frightening reaction after eating is anaphylaxis,” says Nsouli. If EoE isn’t diagnosed early, it can lead to the oesophagus narrowing due to scarring. Each year the disease isn’t treated, the risk of this complication rises by 9 per cent. “When throat tightness, difficulty swallowing or food impaction recur, especially with food allergy testing, we should think about eosinophilic oesophagitis,” says Nsouli. “Rapid recognition can prevent years of uncertainty and progressive oesophageal damage.” In the second study, Bushra Tbakhi at the University of Cincinnati, Ohio, and her colleagues used health records from more than 300 million people in the US and identified more than 500,000 people living with EoE. The number of diagnoses has risen about sevenfold since 2009. The cause of EoE hasn’t been clearly identified, but Tbakhi and her colleagues found several key factors that predisposed patients to the condition. Men were more likely to develop EoE compared with women, and the diagnoses were most common in teenagers and people in their 40s. Those with other inflammatory and allergic conditions, such as asthma, coeliac disease, eczema and food allergies, were more likely to have EoE. Out of the most common food allergies, wheat allergy had the strongest link to the condition. “We are seeing increased eosinophilic oesophagitis over time,” says Tbakhi. “Associated allergic conditions may help identify patients at high risk for eosinophilic oesophagitis.” EoE is a chronic condition with no known cure. The aim of treatment is to control inflammation and symptoms, so patients can live a relatively normal life. People with EoE may benefit from changes to their diet, including cutting out foods that trigger their symptoms. The most common medical treatment for the condition is a class of drugs called proton pump inhibitors. These medications work by blocking the lining of the oesophagus from releasing eotaxin-3, a chemical signal that attracts eosinophils. It also reduces acid production in the stomach, which reduces acid reflux into the throat, allowing the oesophagus to restore its barrier. Swallowed steroids are also used to quickly reduce inflammation in the oesophagus.