The growing prevalence of the rare allergic disease Eosinophilic Oesophagitis

Since it was formally recognised in 1993, the chronic allergic disease Eosinophilic Oesophagitis has become increasingly prevalent in Ireland, writes Gary Markey, PhD student, Department of Biology
Food allergies as well as other allergic disorders are increasing worldwide year-on-year and what were once deemed rare allergic diseases are becoming more prevalent.

Eosinophilic Oesophagitis (EoE) is an emerging chronic allergic disease of the oesophagus and is more recognised now as an increasing clinical problem, affecting as many as 16 in 100,000 people in Europe.

Although EoE is a rare disease, its prevalence is increasing since its discovery approximately 20 years ago. It was first described in 1993 by an Irish trained surgeon Dr Stephen Attwood and his colleagues in the United States.

Since then, EoE has been included within the 'allergic march', whereby patients have an increased chance of being diagnosed with multiple allergic conditions, such as asthma, atopic dermatitis, and rhinitis.

EoE gets its name from the immune cells eosinophils. These immune cells make up just 1% of the total white blood cell population forming the immune system and are significantly increased in allergies and the oesophagus of EoE patients. It can impact people of any age, with males three times more likely to develop the disease than females.

In Ireland, statistics show that approximately 5% of children, and 3% of adults suffer from food allergies. EoE is an oesophageal specific food allergic disease where it is thought that the oesophageal epithelial barrier, the physical boundary between external environmental particles such as food and the underlying immune system, is broken causing inflammation.

This broken barrier is seen throughout other allergic conditions, such as asthma atopic dermatitis, and allergic rhinitis, and further solidifies EoE as a member of the growing allergic march.

Common symptoms associated with EoE include difficulty swallowing, acid reflux, abdominal pain, and food impaction within the oesophagus.

Children with EoE are often deemed as 'fussy eaters' and may lack the proper skills to communicate their symptoms, therefore weight loss is sometimes evident among younger patients. As a result, patients with EoE and families can experience very poor quality of life.

Food triggers for patients suffering from EoE vary from person to person, with the most common triggers being dairy, egg, soy, peanut/treenuts, seafood/shellfish, and wheat.

Environmental allergens, such as pollen, dust mites and air pollution have shown to contribute to EoE rates with some patients displaying seasonal variation with diagnoses in spring and summer.

EoE is a disease with no cure and current mainstays for treatment include elimination diets, acid suppression, and topical corticosteroids. Acid suppressors (proton pump inhibitors) reduce the build-up of acid in the stomach and have been shown to reduce inflammation in a sub-population of patients with EoE.

Gary Markey is a PhD student at the Allergy Inflammation and Remodelling Research Lab at the Department of Biology at Maynooth University, and a Lonsdale Institute for Human Health Research scholarship awardee.

(Front photo credit: Providence Doucet on Unsplash)