Oral and upper gastrointestinal Crohn's disease: new perspectives on pathogenesis and clinical management.

Crohn's disease is a chronic inflammatory bowel disease that is closely associated with genetic factors, immune dysregulation and microbial imbalance. Lesions involving the oral cavity and upper gastrointestinal tract constitute a common yet clinically overlooked manifestation of this disease. This article reviews the cellular and molecular mechanisms underlying disease onset and progression, and evaluates the diagnostic performance of various noninvasive and serum biomarkers. It also summarizes multimodal diagnostic approaches and corresponding therapeutic strategies based on current clinical practice. Currently, relevant clinical trials and standardized evaluation criteria remain lacking, largely because of the limited understanding of disease pathogenesis. Therefore, high-quality basic and translational research will be essential to deepen the understanding of this disease and facilitate the development of precision diagnostic and therapeutic strategies.