The prevalence and incidence of eosinophilic esophagitis appear to have increased over the past 30 years, with most of the cases being diagnosed in late summer and early fall, Dr. Ganapathy Prasad and his colleagues reported.
It's not entirely clear whether the increases represent a true spike in the disease or reflect the parallel increase in upper endoscopies performed over the study period, wrote Dr. Prasad of the Mayo Clinic, Rochester, Minn., and his coauthors. “Though the incidence of eosinophilic esophagitis appears to be increasing, it is possible that an increase in rates of endoscopic evaluation and acquisition of esophageal biopsies … may be responsible in part for this increase,” they wrote.
The researchers conducted a retrospective review of eosinophilic esophagitis in Olmsted County, Minn., using the Rochester Epidemiology Project. They examined data from 1976 through 2005. The incidence of eosinophilic esophagitis increased significantly over the last 15 years of the study, from 0.35/100,000 person-years in 1991-1995, to 9.45/100,000 person-years during 2001-2005. Prevalence was calculated to be 55 cases/100,000 person-years by the end of 2005.
Endoscopies increased during the same period, from about 100/year to about 2,000/year.
The researchers identified 55 adult cases and 23 pediatric cases. The mean age was 37 years among adults and 10 years among children. Dysphagia was the most common presenting symptom in adults and children (93% and 61%, respectively). Food impaction was more common in adults (42% vs. 22%), as was acid reflux regurgitation (38% vs. 22%).
Thirty-seven patients had both proximal and distal esophageal biopsies taken. Of these, 25 had more than 15 eosinophils/high-powered field in both samples, 10 had them in only the distal sample, and the remaining 2 patients had them only in the proximal sample. Of the five patients who had 24-hour pH studies done, distal esophageal acid exposure was normal in four and only mildly abnormal in one.
Treatment was mostly with inhaled steroids (51%); 40% also received a proton pump inhibitor and 20% received both medication and esophageal dilation.
Recurrences occurred in 32 patients, with 32% having a recurrence within 2 years of initial diagnosis and 49% having a recurrence within 4 years.
Among 56 patients contacted in a follow-up interview, 27 (48%) reported dysphagia within the past 3 months; 11 of these reported symptoms “usually” or “often” and the rest said dysphagia occurred “sometimes.” Five patients (9%) said they had visited an emergency department for food impaction within the last year, and 23 (41%) reported receiving either dilation or medications, or both.
The review showed that 60% of the diagnoses were confirmed in the late summer and fall. This may speak to an allergic component of the disease postulated by some researchers.
The study was supported in part by the National Institutes of Health and GlaxoSmithKline. Dr. Prasad reported no conflicts. However, two of the coauthors reported receiving research funding from GlaxoSmithKline and other drug companies.