Aim of the study:
The aim of the study was to determine the prevalence and types of extraintestinal manifestations (EIMs) in paediatric-onset inflammatory bowel diseases (IBD), i.e. Crohn’s disease (CD) and ulcerative colitis (UC), depending on disease activity and location, and to determine whether the presence of EIM is associated with a distinctive clinical course of IBD.

Material and methods:
The medical records of 287 children with IBD with or without EIMs were retrospectively analysed, especially regarding the following characteristics: age at diagnosis, clinical symptoms, nutritional status, the Paris Classification, and IBD activity.

Results:
The study population of 287 children comprised 147 patients with UC (mean age 12.9 years) and 140 patients with CD (mean age 14.1 years). EIMs were diagnosed in 60 patients (20.9%). The most frequent immune-related EIM in UC patients was primary sclerosing cholangitis (PSC); the collective proportion of PSC and PSC/autoimmune hepatitis (AIH) was 14.9%. Arthropathy was the most prevalent EIM in the subpopulation of CD participants (10%). Pancolitis was a risk factor for EIMs in the UC patients (E4/E0-3 OR 2.3, 95% CI 1.05–5.06, p = 0.037), and especially for PSC and AIH/PSC (OR 2.77, 95% CI 1.09–7.06, p = 0.032). Nevertheless, patients with EIMs presented with bloody diarrhoea less frequently (69% vs. 90%, p = 0.011). The CD EIM(+) and EIM(–) patients did not differ significantly regarding the symptoms at hospital admission. No correlation was revealed between disease location or behaviour and EIM occurrence. The impact of the presence of EIM on CD activity is inconclusive.

Conclusions:
EIMs are a significant issue in the population of children with IBD; they developed in 20.9% of our patients. Determination of the prevalence of these manifestations and related risk factors might raise awareness of the problem and facilitate diagnosis and therapy.