That they may be at higher levels than that of other inflammatory gastrointestinal disorders, such as Crohn's disease or ulcerative colitis.

"Despite this explosion in incidence rates, there is so little information available about the disease that patients often suffer for a number of years before a diagnosis is made," says Marc E. Rothenberg, M.D., Ph.D., director of allergy and immunology at Cincinnati Children's Hospital Medical Center and the study's senior author.

The researchers also discovered a familial pattern to the disease, which suggests either a genetic predisposition or a relationship to an unknown environmental exposure, either of which warrant further study, according to Dr. Rothenberg.

Eosinophilic esophagitis (EE) is characterized by severely elevated levels of eosinophils -- a type of white blood cell – in the esophagus. These eosinophils grow in an uncontrolled manner and attack the gastrointestinal system, leading to vomiting and difficulty with growth and swallowing food (dysphagia). EE differs from esophageal reflux in the magnitude of eosinophils that are recruited into the gastrointestinal tract and the lack of response to anti-reflux medications.

EE is just one a group of disorders called eosinophilic gastrointestinal diseases that are often associated with allergies. EE is an emerging disease throughout the world, as documented by recent series of cases in the United States, England, Japan, Spain, Australia, Switzerland and Italy.

"This newly recognized eosinophil and possibly allergic based GI disease is of great interest as it reflects, on an epidemiologic level, a worldwide increase of new allergic inflammation-based disorders," says Lanny J. Rosenwasser, M.D., the Marjorie and Stephen Raphael Chair in Asthma Research and Professor, Allergy and Immunology, at National Jewish Medical and Research Center in Denver. "Understanding the mechanisms and pathogenesis of these disorders is of pressing importance," adds Dr. Rosenwasser, who was not involved in the study.

Dr. Rothenberg conducted the study with Philip E. Putnam, M.D., a pediatric gastroenterologist at Cincinnati Children's, and Richard Noel, M.D., Ph.D., a former fellow in gastroenterology at Cincinnati Children's.

To determine the incidence of EE, Dr. Rothenberg and his colleagues at Cincinnati Children's examined cases of EE in patients from Hamilton County that were identified at Cincinnati Children's, which is the only provider in the region with a pediatric gastroenterology and pathology departments. Between 1991 and 2003, 315 cases met diagnostic criteria for EE, based on the pathology department's database. Only 2.8 percent of these cases were identified prior to 2000. Of the 315 cases, 103 resided within the county.

Incidence rates of EE have not been reported in any other region of the United States, so national incidence rates are impossible to determine. If rates are the same as they are in Hamilton County, the annual occurrence of this disease would be one in every 10,000 children, or approximately 22,000 children in the United States, according to the researchers, who base that estimate on U.S. Census Data.

Cincinnati Children's is a leading international referral center for eosinophilic disorders, with more than 300 patients. Physicians at Cincinnati Children's evaluate about three new patients each week. Because of the significance of this emerging medical disorder, Dr. Rothenberg recently asked the Ohio Board of Health and the Centers for Disease Control to investigate it more thoroughly. In the meantime, Cincinnati Children's is about to launch the first center in the nation for eosinophilic disorders. This center will be designed to provide state-of-the-art clinical care and research.

The rising concern about this disorder has sparked the interest of many families across the nation who are affected by this disease. They recently developed an organization to support increased public awareness and research initiatives, called the American Partnership for Eosinophilic Disorders (APFED). Among the initiatives in which APFED is involved are clinical trials directed by Dr. Rothenberg. Last week, another organization, the Campaign Urging Research for Eosinophilic Disorders (CURED) presented Dr. Rothenberg with $81,000 to be used exclusively as early seed money to support finding a cure for this disease.