Frequency of extraintestinal involvement in patients with inflammatory bowel disease and the relationship with disease activation

Objective: Inflammatory bowel disease (IBD) is a chronic, inflammatory condition of the gastrointestinal tract with an unknown cause. It includes three disease groups: Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis. In the course of inflammatory bowel diseases, extraintestinal manifestations affecting the musculoskeletal system, skin, eyes, biliary tract, and many other systems can be observed in 1/3 of patients. Rheumatological involvement is most commonly seen as peripheral and axial arthritis; skin involvement often manifests as erythema nodosum and pyoderma gangrenosum; and eye involvement is most frequently observed as episcleritis and uveitis. Less commonly, lung involvement, primary sclerosing cholangitis (PSC), hyperhomocysteinemia, kidney stones, and osteomalacia may occur. The aim of this study is to examine the frequency of patients with extraintestinal findings among those followed for inflammatory bowel disease at our center and the relationship of the severity of disease activity with these findings. Materials and Methods: This retrospective study was conducted by screening patients diagnosed with inflammatory bowel disease who presented to the Çukurova University Medical Faculty Hospital. A total of 340 patients diagnosed during the specified years in our hospital's information system were examined, and 301 patients who met the inclusion criteria were included in the study. Patients with clear extraintestinal findings were identified. When determining disease activation, patients were evaluated based on clinical, laboratory, endoscopic, and imaging findings. Data analysis was performed using IBM SPSS 22 software. Results: Of the patients included in the study (129 patients), 42.5% had Crohn's disease and 57.5% had ulcerative colitis. Extraintestinal manifestations (EIM) were observed in 26.6% of all patients. The frequency of EIM was 36.7% in CD and 19.1% in UC patients. In both groups, joint involvement was most commonly observed, followed by eye and skin involvement. Peripheral joint involvement was predominant in both groups (UC 80%, CD 65%). Episcleritis was the most common extraintestinal eye finding in both groups (UC 100%, CD 64.3%). During active disease, peripheral joint involvement was observed in 96.7% of patients with EIM. The most common eye involvement during active disease was episcleritis (85%). Erythema nodosum (100%) was the most frequently seen skin involvement during active disease. Conclusion: A review of the literature shows that EIMs are quite heterogeneous and exhibit significant differences in frequency. Identifying factors that could predict EIMs may help clinicians maintain vigilance in this regard. Identifying independent risk factors predicting EIMs, such as the presence of CRP or CD itself, could be very guiding in clinical practice. Keywords: Inflammatory bowel diseases, extraintestinal findings, arthritis, uveitis, episcleritis.