Real-world efficacy of dupilumab in four cases of paediatric-onset fibrostenotic eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is an increasingly prevalent immune-mediated disease that leads to chronic changes in the oesophagus. These changes can include strictures, narrowing, and stenosis, mediated by an interleukin (IL)-13 pathway, which leads to remodelling and fibrosis through increasing migration of fibroblasts and subepithelial fibrosis via collagen deposition 1. IL-13 downregulates TSPAN12, a gene whose expression regulates fibrosis and causes changes in barrier function and higher rates of fibrostenosis in EoE. Dupilumab, a biologic therapy aimed at blocking IL-13, has been shown to improve EoE-related inflammation and fibrosis in clinical trials. We report here four unique patients with documented oesophageal stenosis with inability to pass a paediatric endoscope due to structuring disease, requiring dilation, who had resolution of their oesophageal narrowing following dupilumab therapy.