Eosinophilic Esophagitis (EOE) is a chronic, immune-mediated disease affecting the esophagus, the muscular tube connecting the mouth to the stomach. The disorder is characterized by the buildup of a specific type of white blood cell, called an eosinophil, in the lining of the esophageal tissue. This accumulation causes inflammation and potential injury to the esophagus. The presence of these cells is highly unusual in a healthy esophagus, and EOE requires long-term attention and management, as it is not a condition that is outgrown.
The Mechanism of Eosinophilic Esophagitis
EOE is fundamentally an allergic inflammatory response occurring within the esophagus. The disorder is triggered when the esophageal lining reacts to specific allergens, most commonly certain foods or environmental substances. This reaction initiates an immune cascade that recruits eosinophils to the tissue.
When activated in the esophagus, these white blood cells release proteins and toxic granules, causing chronic inflammation and damage to the esophageal wall. Over time, this persistent inflammation can cause the tissue to remodel, resulting in fibrosis, or the formation of scar tissue. This scarring stiffens the esophagus and can lead to the development of strictures, which are narrowings that impede the passage of food. The condition is closely linked to other allergic disorders, with many patients also having asthma, eczema, or allergic rhinitis.
Recognizing Symptoms in Different Age Groups
The symptoms of EOE are varied and often depend on the patient’s age, reflecting the body’s reaction to the esophageal inflammation. In infants and toddlers, symptoms are frequently non-specific, centering on feeding difficulties. These young children may exhibit feeding refusal, vomiting, or signs of poor weight gain and growth, often termed failure to thrive.
Older children may experience symptoms similar to gastroesophageal reflux disease (GERD), such as chronic abdominal pain or heartburn, which may not improve with typical GERD medications. They may also start to complain of food getting stuck or have difficulty swallowing.
In adolescence and adulthood, the clinical presentation becomes more distinct and localized. Adults predominantly report dysphagia, particularly with dry or dense solid foods. A food impaction, where food becomes firmly lodged in the narrowed esophagus requiring urgent medical removal, is a common presentation. Chest pain is also frequent in older age groups.
The Diagnostic Process
A definitive diagnosis of EOE requires clinical symptoms combined with specific findings from an endoscopic procedure. The process begins when a physician suspects EOE based on symptoms like dysphagia or a history of food impaction. The upper endoscopy is the primary tool used to visualize the esophagus and obtain tissue samples.
During the endoscopy, a gastroenterologist passes a thin, flexible tube to inspect the esophageal lining. While the esophagus may show visual signs like rings, furrows, or white exudates, the tissue can sometimes look normal. Therefore, the most crucial step is taking multiple small tissue samples, or biopsies, from both the upper and lower sections.
These biopsies are examined under a microscope to count the eosinophils present. The diagnostic threshold for EOE is a peak concentration of 15 or more eosinophils per high-power field (eos/HPF). Diagnosis also requires excluding other conditions that cause eosinophil buildup, such as GERD. This often involves a trial of high-dose proton pump inhibitors (PPIs) before confirmation.
Treatment and Long-Term Management
The management of EOE is a long-term commitment aimed at reducing inflammation, alleviating symptoms, and preventing the progression of esophageal damage. Treatment strategies generally fall into three main categories: pharmacological therapy, dietary management, and endoscopic intervention.
Pharmacological options include swallowed topical corticosteroids, such as fluticasone or budesonide, which directly coat the esophagus and suppress the localized immune response. Proton pump inhibitors (PPIs) are another common medical treatment effective in a subgroup of patients, even those without traditional acid reflux. The goal of medical therapy is to achieve histologic remission, meaning the eosinophil count returns below the diagnostic threshold.
Dietary management focuses on identifying and eliminating the food allergens that trigger the inflammation. This can range from highly restrictive elemental diets, which use amino-acid formulas as the sole source of nutrition, to targeted elimination diets that remove the six most common food allergens, such as dairy and wheat.
Endoscopic dilation is reserved for patients who have developed fixed strictures that cause persistent difficulty swallowing. This procedure uses a balloon or plastic dilator to gently widen the constricted segment. Management requires ongoing collaboration between gastroenterologists and allergists to tailor treatment and ensure sustained remission.