Eosinophilic esophagitis is a disease that no one had heard of twenty years ago. Now although it is still not a household term, more and more people are becoming aware of this condition. So it does seem that EE has become more common over time. In fact, other allergic diseases such as food allergies, asthma, and eczema are becoming more frequent. The reason behind this rise is unclear, but there are a number of theories explaining why this has occurred such as Westernization of society, the hygiene hypothesis, or exposure to chemicals in our environment. None of these theories have been confirmed, but the causes are likely due to more than just one reason.
But has the number of eosinophilic esophagitis cases risen? The answer is yes. There are a number of population studies which have looked at and confirmed this rise. One study looked at the rate of New Cases of Pediatric EE in a county in Ohio. A review of a pathology database from a hospital center identified possible cases of EE based on esophageal biopsies. The criteria for diagnosing EE included >24 eosinophils counted per high powered microscopic field as well as other associated inflammatory changes and the absence of eosinophils on GI biopsies outside of the esophagus. This study noted an increase in prevalence over a three-year period from 2000 to 2003 going from 9.9 to 43 cases per 100,000 children. Subsequent reviews of this same demographic area revealed that the incidence of EE had continued to rise. The authors of the study also noted that the annual incidence (number of newly diagnosed cases per year) was 1in 10,000 children, which makes the incidence of EE similar to that of Crohn’s disease – a well-recognized GI disorder.