Lymphocytic Esophagitis Associated With Chronic Severe Psoriasis: A Case Report With Special Reference to Programmed Death-Ligand 1 Expression.

Lymphocytic esophagitis (LE) is a rare type of chronic esophagitis, marked by an increased number of peripapillary intraepithelial lymphocytes (IEL) with little to no presence of intraepithelial granulocytes and intercellular edema. There is currently no established standard for quantifying IEL in the esophageal mucosa. Clinically, LE manifests with a range of symptoms, including difficulty swallowing (dysphagia), indigestion (dyspepsia), nausea, and chest pain. It is more commonly diagnosed in older women and is often associated with tobacco use, gastroesophageal reflux disease, and achalasia, although the exact cause remains unknown. Programmed cell death protein 1 (PD-1) and its ligand (PD-L1) are expressed on the surface of immune and epithelial cells in healthy and tumor tissues, typically in response to various cytokines. We present a new case of LE associated with chronic severe psoriasis, highlighting the role of PD-L1 expression. This supports the immunopathological basis of the disease and its links to other immune and autoimmune disorders, suggesting its potential as a biomarker for distinguishing LE from reflux esophagitis.