Dietary changes resolve EoE in most kids
Eosinophilic esophagitis (EoE) is an immune-mediated inflammatory esophageal disease first described in children in 1995. It is associated with clinical symptoms and with pathologic changes in the esophagus, including peak eosinophil counts equal to or greater than 15 per high-power field (HPF) on esophageal histology.
EoE can present with various symptoms, but feeding aversion, vomiting and failure to thrive are the most common in infants and toddlers. Younger children are more likely to have vomiting and chest and upper abdominal pain; dysphagia and food impaction are characteristic of older children and young adults.
Pediatric EoE also may be associated with respiratory symptoms. In a 2011 study in the International Journal of Pediatric Otorhinolaryngology Extra, Mayo Clinic researchers described children with recurrent coughing and croup attributable to EoE.
In addition, about 75 percent of pediatric patients have coexisting IgE-mediated food allergies, asthma, allergic rhinitis, eczema or a history of seasonal allergies. Some studies indicate that the increased prevalence of EoE — an estimated 1 in every 10,000 children — parallels a corresponding increase in food allergies.
According to diagnostic consensus criteria, the diagnosis of EoE is established when symptoms and pathology persist after an eight-week trial of high-dose proton pump inhibitors (PPIs). But according to Rayna M. Grothe, M.D., a gastroenterologist at Mayo Clinic's campus in Rochester, Minnesota, many children with EoE may not be able to tolerate a full PPI trial.
"Because of significant nutritional and feeding issues, intervention is required to treat the EoE prior to completing a trial of PPIs," she says. "To be able to evaluate and treat EoE properly takes more than the expertise of a gastroenterologist; you need an allergist and a nutritional specialist who can help with growth issues and nutritional deficiencies. The focus at Mayo's new multidisciplinary Pediatric Eosinophilic Esophagitis Clinic is to bring all the subspecialties to the table, so we can individualize treatment."
The close association between food allergies and EoE means the first line treatment in infants and young children is an elemental diet or the elimination of specific food allergens.
Elemental diets have a 97 percent response rate, leading to complete remission in the vast majority of patients. But the amino acid-based formulas, which are expensive and only sometimes covered by insurance, are often poorly tolerated because of their unpalatability or, in older children, the need for enteric feeding. They also require strict monitoring for nutritional deficiencies that could adversely affect normal development in young patients.
An empirical six-food elimination diet, which removes the most common allergenic foods — milk, soy, eggs, wheat, seafood and nuts — is a more practical modality effective in about 75 percent of patients. Another approach relies on targeted diets that eliminate foods to which a child has a known IgE-mediated allergy, such as corn or wheat.
Whatever the approach, eliminated foods are gradually reintroduced after symptoms and eosinophilia resolve.
Dr. Grothe explains: "On the six-food elimination diet, we add soy first, then egg, and then wheat and milk. We usually keep a child on the added food for one month and then reassess the child's tolerance before adding another food. We pay attention to what the data suggest are the most likely to cause a reaction, including utilizing skin prick testing and serologic IgE antibody testing in addition to assessing symptoms. It's not an exact science yet because there is no specific type of food allergy test that has been correlated with 100 percent certainty with the development of EoE. Making decisions about what a child eats requires great care because of the nutritional and social implications."
Because so many issues with pediatric EoE involve growth and development, it's important to have allergists and dietitians involved, says Karen A. Marolt, R.N., nursing care coordinator for the EoE clinic. "We have a detailed plan for each patient, and work closely with families and the doctor during follow-up," she says. "When we start reintroducing foods back into the diet, we like to see the child back for clinical reassessment and possible repeat endoscopy in a month.
"We try to limit the number of endoscopies, and have looked at various noninvasive ways to monitor recurrence, including the esophageal string test, blood proteins and buccal swabs, but none has given consistent results. It would be a big breakthrough in clinical management if we could find noninvasive biomarkers to assess the effects of oral food challenges. Further understanding of the genetics of EoE may be helpful in the future to predict therapeutic response to specific interventions."
Inhalant-sensitive children and young adults usually benefit from topical corticosteroids, though the relapse rate when treatment is discontinued is high, says Sharon Muller, R.N., C.N.P., also of the EoE clinic. "EoE can be PPI responsive, so our first decision is whether to keep patients on these medications. Then we add in a topical steroid — some use inhaled fluticasone or budesonide. At Mayo, we use Pulmicort solution in a viscous solution, but we're looking at other forms of topical steroids that are more palatable."
EoE is a relatively newly discovered disorder and is still associated with diagnostic, therapeutic and prognostic uncertainties. Dr. Grothe says the new pediatric EoE clinic is poised to help resolve some of them. "There is so much to be learned, and one of the reasons to have a multidisciplinary clinic is to get all the specialists in one room and tease out some of the answers," she says.
For more information
Dornier BD, et al. Aerodigestive manifestations of eosinophilic esophagitis in Rubenstein-Taybi syndrome. International Journal of Pediatric Otorhinolaryngology Extra. 2011;6:355.