11Pediatric Gastroenterology, Department of Pediatrics, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands; 2Department of Pediatric Gastroenterology and Nutrition, The Medical University of Warsaw, Warsaw, Poland; 3Gastroenterology and Nutrition Unit, Meyer Pediatric Hospital, Florence, Italy; 4Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands; 5Department of Pediatric Gastroenterology, Queen Mary's Hospital for Children, Surrey, United Kingdom; 6First Department of Pediatrics, Athens University, Athens, Greece; 7Department of Pediatrics, Charles University in Prague, Hradec Kralove, Czech Republic; 8Department of Pediatric Gastroenterology, Helsinki Children's Hospital, Helsinki, Finland; 9Pediatric Gastroenterology Unit, Meyer Children's Hospital, Haifa, Israel; 10Department of Pediatrics, University of Naples, Naples, Italy; 11Department of Pediatric Gastroenterology, Radboud University Medical Centre, Nijmegen, the Netherlands; 12Department of Pediatric Gastroenterology, VU University Medical Center, Amsterdam, the Netherlands; 13Department of Pediatrics, Juliana Children's Hospital, The Hague, the Netherlands; 14Department of Pediatrics, Medical Center Alkmaar, Alkmaar, the Netherlands; and 15Pediatric Gastroenterology Unit, Shaare Zedek Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel.
Inflammatory bowel disease-unclassified (IBD-U) is diagnosed in ∼10% of pediatric and adolescent onset IBD patients. The EUROKIDS registry (2004) initiated by the Porto IBD working group of ESPGHAN prospectively monitors diagnostic workup of newly diagnosed pediatric and adolescent onset IBD patients. We aimed to describe diagnostic workup, phenotype, and change of diagnosis over time in pediatric IBD-U patients.
Data were collected on children from 52 centers across 20 European countries and Israel, diagnosed with IBD from May 2005 through November 2013. Full endoscopy plus small bowel radiology was considered complete diagnostic workup. Participating centers reporting IBD-U patients were queried in 2014 for follow-up data.
IBD-U was the provisional first diagnosis in 265 of 3461 children (7.7%) (91/158 [58%] with pancolitis; 140 [53%] male), diagnosed more frequently under the age of 10 (median age 12.3 years, 89 [34%] under 10 years). Half (48%) had undergone complete diagnostic workup. Lack of small bowel radiology was the prevailing reason for incomplete workup. As a result of reinvestigations (endoscopy in 54%, radiology in 38%) during a median follow-up of 5.7 years (interquartile range, 2.5-7.8), a change in diagnosis from IBD-U to Crohn's disease (12%) or ulcerative colitis (20%) was reported.
Only half of patients reported as IBD-U in EUROKIDS had undergone complete diagnostic workup. Follow-up with reinvestigations resulted in a reduction of IBD-U rate to 5.6%. A diagnosis of IBD-U becomes less likely in case of complete diagnostic workup. Implementation of clear diagnostic criteria will further reduce the rate of IBD-U in the future.