The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway plays a critical role in orchestrating immune and inflammatory responses, and it is essential for a wide range of cellular processes, including differentiation, cell growth, and apoptosis. Over the years, this pathway has been heavily investigated due to its key role in the pathogeneses of several chronic inflammatory conditions, e.g., psoriasis, atopic dermatitis (AD), and inflammatory bowel diseases (IBDs). Nevertheless, the impact of this pathway on the pathogenesis of inflammatory conditions remains unclear. This review describes the role of the JAK/STAT signaling pathway in the pathogenesis of inflammatory diseases such as psoriasis (Pso), psoriatic arthritis (PsA), AD, and IBD with a focus on ulcerative colitis (UC) and briefly resumes the use of JAK inhibitors in their clinical management.

Introduction: Multiple imaging modalities are often required for the relapsing nature of Crohn disease (CD). Computed tomography (CT) offers a rapid acquisition of images and shows high specificity and sensitivity. However, CT imaging exposes to a higher dose of ionizing radiation than other abdominal imaging modalities. The aim of this study was to compare the use of preoperative and postoperative CT scan in patients undergoing emergency and elective surgery for CD. Methods: All patients undergoing emergency and elective surgery for ileocaecal CD January 2014 to December 2018 were included in this prospective observational study. The study objective was to evaluate the frequency of use of CT scan perioperatively with the number and findings of preoperative and postoperative CT being the primary outcomes. The secondary outcomes were operating time, length of hospital stay, reoperations, and rehospitalization. Results: A total of 75 patients were included, 33 in the emergency group (43%) and 44 in the elective group (57%). There was a higher use of preoperative CT scan in the emergency surgery group, with 14 patients (42%) having a CT scan before surgery compared with 2 (5%) in the elective group (P=0.14). Thirteen patients (39.4%) had a postoperative CT scan in the emergency surgery group, compared with 10 patients (23.8%) in the elective surgery group. Conclusion: Patients undergoing emergency surgery for CD are at increased risk of exposure to ionizing radiations due to high perioperative use of CT scan.