Oesophageal web. Endoscopic image of a web in a patient's oesophagus (gullet). Oesophageal webs are thin membranes that can occur anywhere along the oesophagus. They are mainly observed in the Plummer-Vinson syndrome, which is associated with chronic iron deficiency anaemia. They are also associated with bullous diseases (such as epidermolysis bullosa, pemphigus, and bullous pemphigoid).