MONTREAL — The incidence of adult and pediatric eosinophilic esophagitis appears to be increasing dramatically, and endoscopic investigation and treatment have low complication rates, according to the findings of the largest reported population-based study of the disorder.
Dr. Chad Williams and his colleagues from the University of Calgary (Alta.) found an incidence of 7.2 cases/100,000 person-years in 2006 in the Calgary Health Region (population 1.2 million), the highest incidence to date, they reported in a poster at the Canadian Digestive Diseases Week.
“The number of diagnoses per year is definitely rising,” Dr. Williams said in an interview. “Whether that reflects a true increase in incidence we're not sure. We may be just recognizing it more.”
Few studies have investigated the incidence of eosinophilic esophagitis in general, and none has addressed the incidence in the adult North American population in particular, he said. A European study reported an adult incidence of 6 cases/100,000 person-years (J. Allergy Clin. Immunol. 2005;115:418–9).
In their retrospective cohort study, Dr. Williams and his colleagues identified adult and pediatric biopsy-proven cases of eosinophilic esophagitis in the Calgary Health Region between 2002 and 2006. Overall, there were two cases identified in 2002, and no cases in 2003. However, the reported incidence rose dramatically from 1.83 cases/100,000 person-years in 2004 to 4.27 cases in 2005 and to 7.2 cases in 2006.
The incidence per 1,000 upper endoscopies rose from 2.16 cases in 2004 to 8.35 cases in 2006.
The incidence seemed to increase in adults, while it dipped among children. The number of cases in adults went from 5 in 2004 to 75 in 2006, compared with 16 in 2004 to 6 in 2006 in children.
Among the total of 158 identified cases, 75% of them were adults and 84% were male. The median age of adult patients was 39 years, and the median pediatric age was 12 years.
“In the pediatric population, patients usually present with food aversion, gastroesophageal refluxlike symptoms and abdominal pain, but in the adult population, the two main symptoms are dysphagia and food bolus impaction,” Dr. Williams explained at the conference, which was sponsored by the Canadian Association of Gastroenterology.
In a subanalysis of 144 of the eosinophilic esophagitis cases, the mean age of the patient population was 40 years (range 16–78 years), Dr. Williams' group reported in another poster.
Most (85%) of the patients were male; 74% presented with dysphagia and 18% with food impaction. Allergies were noted in 27% of patients, asthma in 22%, gastroesophageal reflux disease in about 20%, and autoimmune disease in about 3%. All of the patients underwent endoscopic evaluation and biopsy, with 22% of patients also receiving concurrent therapeutic esophageal dilation.
Endoscopic complications were more common in patients undergoing dilation, with six mucosal tears documented, but no perforations, Dr. Williams said.
In patients undergoing endoscopic biopsy alone, there was one mucosal tear resulting from the biopsy, and one resulting from trauma from the endoscope. Dr. Williams noted that overall this complication rate was low, compared with a previously reported rate of 30% (Clin. Gastroenterol. Hepatol. 2007;5:1149–53).
“Gastroscopy is a fairly safe procedure, although we did have one mucosal tear in our group, but I am not a proponent of dilation in this population,” Dr. Williams said, adding that he recommends medical treatment with fluticasone as the first-line therapy.
Eosinophilic esophagitis (shown on endoscopy) is being detected more often. Courtesy Dr. Chad Williams