Thursday, July 7, 2011

Article: New Eosinophilic Esophagitis Guidelines Update Diagnosis, Therapy

New Eosinophilic Esophagitis Guidelines Update Diagnosis, Therapy

New clinical guidelines for eosinophilic esophagitis characterize the disorder as a chronic, immune- and antigen-mediated disease.

The updated consensus recommendations, which constitute the first update since 2007, also suggest that eosinophilic esophagitis (EoE) is truly on the rise in both adults and children, although no one really knows why, according to Dr. Chris A. Liacouras, first author of the paper. The guidelines also suggest for the first time that the disease may have a genetic underpinning – an abnormality in chromosome 5.

In addition to a genetic predisposition, an increase in food allergies may be at the root of the growing incidence, Dr. Liacouras said in an interview.

"This disease is exploding, and many of us believe that foods are responsible. But we don’t know exactly how," said Dr. Liacouras, professor of pediatrics at the University of Pennsylvania, Philadelphia, and codirector of the Center for Pediatric Eosinophilic Disorders at the Children’s Hospital of Philadelphia. "In the 1950s and ’60s, we were pretty much eating the same kinds of the foods that we do today, and the genetics were there, although still unknown. There is something different going on now – maybe something in the way foods are processed," although there are no data yet to support that theory.

Of course, he added, physicians are also "getting better at looking for it and identifying it when we see it."

The paper, printed in the July issue of the Journal of Allergy and Clinical Immunology, combines the diagnostic, treatment, and research recommendations of 33 pediatric and adult gastroenterologists, immunologists, and allergists (J. Allergy Clin. Immunol. July 2011;128:3-20.e6). "The big thing that we are excited about is that this is one of the few times where the pediatric and adult specialists are working together as one group," Dr. Liacouras said.

In addition, pediatric patients seem to be presenting with more advanced disease since the 2007 report was released, he said. "Pediatric gastroenterologists have looked at this and biopsied it for years, but we have never seen this degree of rings and strictures [in children]."

Defining aspects of the new diagnostic criteria include histology results from multiple biopsies, as well as clinical findings. "The problem, especially for adults, has been that a lot of gastroenterologists have expected the pathologist to tell them what’s happening," Dr. Liacouras said. "[Pathologists] can only describe what they’re seeing, so the clinician has to see clinical findings as well as eosinophils to make treatment decisions."

According to the guidelines, "With few exceptions, 15 eosinophils per high-powered field is considered a minimum threshold for a diagnosis of EoE." Other histopathologic findings may include basal cell hyperplasia, dilated intracellular spaces, and lamina propria fibrosis isolated to the esophagus. Because of the disease’s exclusive location in the esophagus, proton pump inhibitors are most often used initially as a way to rule out EoE.

"You want to be sure that reflux acid is not causing this problem. If the patient responds to a proton pump inhibitor, they do not have this disease," said Dr. Liacouras.

Dysphagia, reflux, and heartburn can be early signs, and dysphagia is the most common presenting symptom in adolescents and adults. Infants typically experience feeding problems. "In children, [it] is more often present in association with other manifestations of atopic disorders – food allergy, asthma, eczema, chronic rhinitis, and environmental allergies," the paper notes.

Patch testing is an effective supplemental diagnostic tool, but is not perfect, Dr. Liacouras said. "This disease is not an anaphylactic event, a delayed event, or an immunoglobulin-mediated event, which is why it’s hard to use allergy testing as a diagnostic tool."

Treatment recommendations have evolved since 2007, although children often respond to elimination of typical allergy-inducing foods. Unlike adults, children may be able to reverse the damage when they avoid the problem food or foods. In contrast, adults generally experience a lifelong course of EoE that can only be symptomatically controlled, Dr. Liacouras said.

For both adults and children, topical steroids are usually indicated. These include steroids such as fluticasone, used with a spacer and swallowed instead of inhaled. "Since the 2007 guideline, there’s also an oral viscous suspension of budesonide in sucrose," Dr. Liacouras said. Biologics like infliximab will probably play no role in treating this disorder, he added.

Esophageal dilation can provide relief to some patients, but unless there are high-grade esophageal strictures, it’s reasonable to try medical or dietary therapy first, the authors wrote. Because of an increased risk of perforation, the guidelines advise physicians to use "a more conservative and careful approach" for EoE patients, compared with those who have other benign conditions.

The authors also call for future studies to identify EoE subgroups, further investigate the disease’s genetic underpinning, and study the role of allergy testing. Pediatric and adult specialists should continue their joint efforts to improve diagnostic criteria and determine the optimal therapy.

"The joint effort of pediatric and adult clinical and basic scientists in a variety of subspecialties has been paramount in the rapid understanding of this disease process," the paper said. "It is critical that leaders [in basic science, gastroenterology and allergy and immunology] continue to work together and undertake studies on the natural history, pathophysiology, biomarkers, diagnosis, and therapeutic approaches, not only to increase the scientific and clinical knowledge of EoE but also to improve the lives of children and adults affected by the disease."

The authors disclosed potential conflicts of interest including multiple financial relationships with pharmaceutical companies.

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