Abstract
Atopic dermatitis (AD) and ulcerative colitis (UC) are immune-mediated inflammatory diseases (IMIDs) with high prevalence and treatment costs. AD mainly affects the skin, while UC targets the colon and rectum, but both are characterised by immune dysregulation driven by aberrant T helper cell activation, persistent barrier dysfunction, genetic predisposition, and environmental triggers. This overlap may explain the link between the two diseases and the increased risk of UC in patients with AD. Both diseases are chronic, progressive, and limited in treatment options, and there is a need for a better understanding of their mechanisms and biomarkers. To address this, we developed disease maps for UC and AD, covering their molecular mechanisms. Here, we present the development and contents of the maps, as well as demonstrate their application in data visualisation and analysis. Our systematic, interactive comparison reveals both common and disease-specific signatures, as well as common pathological pathways. These findings highlight shared biomarkers for predicting progression and therapy outcomes, and opportunities for drug repurposing. The UC and AD disease maps provide a valuable resource for representing and exploring common and distinct mechanisms, helping to advance IMID management from organ-based symptom relief towards mechanism-based treatments.