Eosinophilic Esophagitis (EOE) is a chronic, immune-mediated condition affecting the esophagus. This disease is recognized as an allergic inflammatory disorder where the lining of the esophagus becomes damaged. The inflammation is driven by an abnormal accumulation of a specific type of white blood cell, leading to tissue injury. Over time, this chronic inflammation can cause the esophageal tissue to become scarred and narrowed, often leading to difficulty swallowing and food getting stuck in the throat.
EOE Is Not a Systemic Immune Deficiency
EOE itself does not cause a patient to be systemically immunocompromised. The condition is a localized problem of immune overreaction, characterized as a chronic allergic response. The immune system is not failing to protect the body; rather, it is inappropriately activating a strong inflammatory reaction in the esophagus. This is fundamentally different from systemic immunodeficiency disorders, which involve a general failure of the immune system to fight off infections throughout the body.
The disease involves an overactive inflammatory response to triggers, such as food or environmental allergens, not an underactive one. The allergic reaction is largely confined to the mucosal lining of the esophagus, making it a highly localized immune dysfunction. Therefore, having EOE does not inherently increase a person’s susceptibility to common infections like colds, flu, or pneumonia.
The Role of Eosinophils in Esophageal Inflammation
The hallmark of EOE is the presence of eosinophils, a specific type of white blood cell, in the esophagus where they do not normally reside in significant numbers. Eosinophils are known for their role in fighting parasitic infections and contributing to allergic reactions. In EOE, these cells are mistakenly recruited to the esophageal lining in high concentrations.
Once accumulated, activated eosinophils release inflammatory chemicals and toxic proteins. This release directly causes inflammation and injury to the surrounding esophageal tissue. Over a prolonged period, this sustained cellular activity leads to tissue remodeling and the development of scarring or fibrosis.
How EOE Treatments Impact Systemic Immunity
While EOE itself does not cause systemic immune suppression, some medications used to treat the inflammation carry a risk of impacting overall immune function. The most common first-line therapy involves swallowed topical corticosteroids, such as fluticasone or budesonide. These medications are designed to work directly on the esophageal lining to reduce inflammation with minimal absorption into the bloodstream, keeping the risk of systemic immune suppression low.
Even topical corticosteroids may carry a small risk of affecting the adrenal glands, particularly with high-dose or prolonged use. In contrast, systemic oral corticosteroids, like prednisone, are sometimes used for short periods to manage severe flare-ups. These oral medications are absorbed throughout the body and are known to cause temporary, dose-dependent systemic immune suppression. Patients taking systemic steroids may experience an increased susceptibility to infection and should discuss this risk with their physician.
Newer treatments include biologic therapies, suchs as the monoclonal antibody dupilumab, approved for EOE. These agents work by specifically targeting key inflammatory signaling proteins, like Interleukin-4 and Interleukin-13, that drive the allergic response. Because biologics modulate specific parts of the immune pathway, patients initiating these targeted therapies must consult with their healthcare provider to understand any changes to their infection risk profile, especially regarding live vaccines.