The largest investigation to date has found a significant increase in the number of acute pancreatitis (AP) cases in hospitalized children in the United States.

The new study, in the PLOS ONE journal found a 51 percent increase in the primary diagnosis of AP from 2000 to 2009. The number increased from 6,350 in 2000 to 9,561 in 2009.

The study looked at hospitalization records of patients 20 years old and younger using a federal children's inpatient database. From 2000 to 2009, they identified 55,012 cases of AP in hospitalized children ages 1 - 20.

According to the study's principal investigator, Thomas J. Sferra, MD, Division Chief of Pediatric Gastroenterology, Hepatology and Nutrition at UH Rainbow Babies & Children's Hospital and Associate Professor of Pediatrics at Case Western Reserve University School of Medicine, hospitalized children with AP had longer hospital stays and higher charges. And AP was more likely to occur in children older than 5 years of age.

AP is the reversible inflammation of the pancreatic parenchyma. In children the most frequently identified causes of AP are biliary tract disease, medication adverse effect, systemic disease and trauma.

"The reason for this large increase in acute pancreatitis cases in hospitalized children is not clear," said Dr. Sferra. "Though the incidence of AP is increasing, there has been an improvement in the mortality and length of stay of these patients. These data provide a good foundation for future studies to increase our understanding of the disease."