Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease affecting the esophagus, the tube connecting the mouth to the stomach. This condition involves the buildup of specific white blood cells, called eosinophils, in the esophageal lining. This article explores the prevalence of EoE, its underlying mechanisms, and the factors contributing to its occurrence.
Understanding Eosinophilic Esophagitis
In individuals with EoE, eosinophils accumulate in large numbers within the esophageal lining. This accumulation triggers inflammation, leading to damage and dysfunction of the esophageal tissue. Common symptoms of EoE vary by age but often include difficulty swallowing (dysphagia), food impaction, and heartburn. Young children might exhibit feeding difficulties, vomiting, or poor growth, while adults primarily experience swallowing issues and food impaction.
Diagnosing EoE involves an esophagogastroduodenoscopy (EGD), where a gastroenterologist examines the esophagus. During this procedure, biopsies are taken from the esophageal lining. A pathologist then examines these biopsies under a microscope to confirm the presence of an abnormally high number of eosinophils. While the esophagus may sometimes show visible signs like rings or white plaques, a biopsy is crucial as the esophagus can appear normal despite the presence of EoE.
Global Prevalence and Incidence
EoE has emerged as a recognized condition, with its prevalence and incidence increasing significantly across the globe. The global pooled prevalence of EoE was estimated at approximately 40.04 cases per 100,000 people between 1976 and 2022. The global pooled incidence was about 5.31 cases per 100,000 people during the same period. Some reports suggest incidence rates of 5–10 new cases per 100,000 inhabitants annually, with some countries reporting up to 20 new cases.
Prevalence estimates in the U.S. range from 40–90 cases per 100,000 individuals. EoE affects both children and adults, though it is more frequently reported in children and younger adults. Data indicates a consistent male predominance, with males affected three to four times more often than females, and it is also more common in individuals of White descent. The highest prevalence rates have been reported in North America and Europe.
Factors Influencing EOE Occurrence
Several factors are associated with the development of EoE. A strong connection exists with other allergic conditions, as many individuals with EoE also have asthma, allergic rhinitis, atopic dermatitis, or food allergies. EoE can also run in families, suggesting a genetic predisposition.
Environmental triggers, such as certain foods or airborne allergens, are believed to play a role in causing the immune system to react and accumulate eosinophils in the esophagus. Geographical factors, including living in cold or dry climates or areas with lower population density, have also been linked to higher rates of EoE. The exact reasons for these associations are still under investigation.
Is EOE Truly More Common?
The observed rise in EoE cases is likely due to a combination of increased awareness and improved diagnostic capabilities, alongside a potential true increase in incidence. Healthcare professionals are more aware of EoE, leading to a higher suspicion for the condition and more frequent endoscopic procedures with biopsies.
Beyond improved detection, research suggests a genuine increase in EoE cases, paralleling the rise in other allergic diseases. Theories such as the “hygiene hypothesis” propose that modern, clean environments may alter immune system development, leading to allergic responses. Changes in diet, delayed introduction of food allergens, and shifts in bathing practices are also being explored as potential environmental factors contributing to this trend.