Extraintestinal Manifestations of Inflammatory Bowel Disease Original paper

What was studied?

This review article explores the extraintestinal manifestations (EIMs) associated with inflammatory bowel disease (IBD), particularly focusing on Crohn’s disease (CD) and ulcerative colitis (UC). It discusses the prevalence, pathophysiology, and various manifestations that affect organs and systems outside the gastrointestinal tract, such as dermatological, ophthalmological, musculoskeletal, hepatobiliary, and other organ systems. It also touches on potential causal mechanisms and associations with IBD treatments.

Who was studied?

The study primarily focuses on a wide range of patients with IBD, drawing data from both adult and pediatric populations. The article highlights findings from pediatric centers where IBD’s extraintestinal manifestations are reported to be more prevalent compared to general adult populations. Additionally, it emphasizes the associations of EIMs with underlying IBD disease, genetic factors (such as HLA phenotypes), and the treatments used, such as immunosuppressive and biologic therapies.

Most important findings

The article reveals that EIMs of IBD can involve nearly every organ system, with the skin, eyes, joints, and hepatobiliary system being among the most commonly affected. Dermatological manifestations such as erythema nodosum and pyoderma gangrenosum are particularly prevalent in patients with CD. These skin conditions often correlate with the activity of the underlying disease, indicating a shared immune-mediated pathophysiology. Musculoskeletal issues, particularly peripheral arthritis and axial arthropathy (ankylosing spondylitis and sacroiliitis), are also common and significantly impact the quality of life of IBD patients. Additionally, hepatobiliary manifestations like primary sclerosing cholangitis (PSC) are more frequently observed in patients with UC, while non-alcoholic fatty liver disease (NAFLD) and other liver-related complications are common in CD.

The pathogenesis of these manifestations is complex and involves immune system dysregulation, bacterial factors, genetic predispositions, and the impact of IBD treatments. Recent studies in animal models highlight the importance of gut microbiota in the expression of EIMs, particularly in genetically predisposed individuals. Moreover, the role of medications, especially corticosteroids and immunosuppressants, in triggering or exacerbating EIMs has been observed in some patients.

Key implications

Understanding the broad spectrum of extraintestinal manifestations in IBD is crucial for clinicians, as EIMs often present before the onset of gastrointestinal symptoms, complicating the diagnosis. Recognizing these manifestations early can lead to more timely interventions and prevent long-term complications. For pediatric patients, the prevalence of EIMs is notably higher, emphasizing the need for careful monitoring across different age groups. Additionally, since some manifestations, like pyoderma gangrenosum and uveitis, can occur independent of IBD activity, they may require separate therapeutic strategies, which could include immunosuppressive or biologic treatments.