November 8, 1995
Media Contact: Debbie Bangledorf
Phone: (410) 223-1731
Johns Hopkins Children's Center researchers speculate that food allergies -- those not detected with standard tests -- might be the cause of some gastrointestinal problems in children. If proven, their allergy theory could introduce new ways to evaluate and treat kids for problems like severe nausea, pain, vomiting and poor weight gain.
Currently, these children receive medication to stop acid production and even surgery to stop acid regurgitation. According to the study, however, acid reflux may not be the problem at all and treatment may be as simple as restricting certain foods. The study appears in the November issue of Gastroenterology.
"Previously, these children were tested for food allergies, but traditional skin tests were negative," says Kevin Kelly, M.D., who directed the study when he was at Hopkins. "When they didn't improve with common therapies, we tried to approach the problem from a different perspective."
According to Kelly, biopsies of 10 patients revealed eosinophil cells in the esophagus, a common sign of acid reflux.
"We originally thought that the eosinophils were present because of acid production and reflux. Because of this study, we now think that they are the result of a hypersensitive reaction to ingesting food proteins," he says.
To prove their theory, the researchers took away most foods and placed the children, ages 8 months to 12 years, on an amino-based formula for an average of 17 weeks. The formula is free of the proteins that trigger allergic responses but provides adequate daily calories with the proper distribution of carbohydrates, fats, vitamins, and minerals for growth.
In addition to the formula, patients were allowed clear liquids and foods made from apples and corn, since children rarely are allergic to them.
During the trial, eight of 10 patients quickly became free of chronic gastrointestinal complaints and two reported substantial improvement. Biopsies showed lower or no eosinophils in all 10 patients.
To further support the allergic hypothesis, the patients were gradually reintroduced to specific foods, such as milk, soy, wheat, peanuts, and eggs. The gastrointestinal symptoms were recreated in 9 of the 10 patients, by one or more of these foods. When the allergy-causing food was identified and eliminated, patients again improved. Eight of the 10 patients eventually stopped chronic anti-reflux medications.
Kelly says that although these amino-based formulas are reasonable tools to uncover allergies, further studies need to be done to determine just how protein sources in the diet interact with the gastrointestinal tract.
Kelly is now director of pediatric gastroenterology at St. Christopher's Hospital for Children in Philadelphia.
Other Hopkins researchers involved in this study include: Jay Perman, M.D., professor of pediatrics; Peter Rowe, M.D., associate professor of pediatrics; Hugh Sampson, M.D., professor of pediatrics; and John Yardley, M.D., professor of pathology. Audrey Lazenby, M.D., a former Hopkins assistant professor of pathology, is now at the University of Alabama at Birmingham.
Funding was provided by the National Institutes of Health, the National Institutes for Allergy and Infectious Diseases, and Scientific Hospital Supplies, Inc. in Gaithersburg, MD, who provided the formula. This study also was supported by Hopkins Pediatric Clinical Research Unit.
The Johns Hopkins Children's Center is the children's hospital of The Johns Hopkins Medical Institutions. Maryland's only comprehensive acute-care hospital for children, the Center, with its 177-bed hospital and more than 40 divisions and services, treats 7,000 inpatients and more than 90,000 outpatients annually.