Abstract
A 12-year-old boy presented with recurrent abdominal pain for more than 5 months and a perianal mass for 10 days. Gastrointestinal endoscopy revealed multiple ulcers in the terminal ileum and colon, and Crohn's disease was diagnosed based on histopathology. The patient had atopic dermatitis and had previously received upadacitinib; after the diagnosis of Crohn's disease, upadacitinib was continued. During a total follow-up of 100 weeks, the patient maintained clinical remission without serious adverse reactions. This is the first report from China on upadacitinib treatment for pediatric Crohn's disease and provides guidance for its use in this population.