The esophagus is a muscular tube that transports food and liquid from the throat to the stomach; its inner lining, or mucosa, is normally smooth and uniform. During an upper endoscopy, a medical professional may observe an abnormal appearance of this lining known as esophageal furrowing. Furrowing is a visible physical manifestation of an underlying inflammatory condition affecting the esophageal tissue. Understanding this finding is important because it often points toward a specific diagnosis requiring targeted medical intervention to prevent long-term complications.
What Esophageal Furrowing Looks Like
Esophageal furrowing appears as multiple, fine, linear lines or ridges that run vertically down the length of the esophageal wall. These markings give the tissue a corrugated or ribbed texture, sometimes described by doctors as a “feline esophagus.” This visual change results directly from chronic inflammation that causes the esophageal lining to thicken and become stiff.
The inflammation leads to tissue remodeling, causing the delicate mucosa to lose its normal elasticity. Instead of stretching smoothly, the tissue bunches up into visible ridges when the esophagus contracts or the endoscope passes through. Furrowing is one of several endoscopic features, including white plaques or rings, that signal a significant, ongoing inflammatory process.
Eosinophilic Esophagitis (EoE)
The most frequent cause of esophageal furrowing is Eosinophilic Esophagitis (EoE). This chronic, immune-mediated disease involves the immune system mistakenly targeting the esophagus, usually in response to food or environmental allergens. The defining feature of EoE is the dense accumulation of eosinophils—a specific white blood cell—within the esophageal lining.
Eosinophils are normally involved in fighting parasites and managing allergic responses, but they are not found in healthy esophageal tissue. When these cells infiltrate the esophageal wall, they release powerful inflammatory mediators, such as cytokines like Interleukin-5 (IL-5) and Interleukin-13 (IL-13). These chemical signals attract more eosinophils and initiate tissue damage and remodeling.
The prolonged presence of these inflammatory cells triggers subepithelial fibrosis, which is the formation of scar-like tissue beneath the mucosal surface. This fibrosis stiffens the esophageal wall, leading to visible furrowing and other structural changes, such as rings and strictures. Patients with EoE commonly experience difficulty swallowing (dysphagia) and episodes of food impaction.
The symptoms seen in EoE relate directly to the physical changes caused by chronic inflammation. The loss of elasticity and the presence of furrows and rings impair the normal muscular contractions needed to push food down. This mechanical dysfunction can necessitate emergency endoscopic procedures to remove impacted food.
Other Inflammatory and Structural Causes
While EoE is the primary cause, other conditions can also cause inflammation resulting in less pronounced linear changes. Chronic, severe Gastroesophageal Reflux Disease (GERD) can sometimes increase eosinophils and inflammation in the lower esophagus. However, the mechanism in GERD is primarily chemical irritation from stomach acid, distinct from the allergic, immune-driven response of EoE.
The esophageal changes seen in GERD are typically erosions or ulcers rather than the classic deep furrows associated with EoE. The number of eosinophils in the tissue is usually much lower in GERD, often fewer than 15 per high-power field, which helps differentiate the two conditions. Infectious esophagitis from fungal or viral agents, particularly in immunocompromised individuals, may also be considered.
Diagnosing the Root Cause and Treatment
Determining the cause of esophageal furrowing requires an upper endoscopy with tissue biopsies. The endoscope allows the physician to visually confirm the furrowing and collect tissue samples from different levels of the esophagus. These biopsies are then examined under a microscope to count the number of eosinophils present.
For an EoE diagnosis, the pathology must show an eosinophil count of 15 or more per high-power field, and other potential causes must be ruled out. If EoE is confirmed, treatment focuses on reducing inflammation to alleviate symptoms and prevent further tissue remodeling and fibrosis. The main approaches involve medication, diet, and procedural intervention.
Medication often includes swallowed topical corticosteroids, such as fluticasone or budesonide, which suppress the inflammatory response directly on the esophageal lining. Proton pump inhibitors (PPIs) are also frequently used, as they can resolve inflammation in a subset of patients (PPI-responsive esophageal eosinophilia). Dietary management involves elimination diets to identify and remove specific food allergens, with common triggers including dairy and wheat. If structural changes like strictures have developed, esophageal dilation may be performed to gently stretch the narrowed areas and improve swallowing function.