The phrase “erythematous mucosa” is often included in upper endoscopy results and can sound concerning to a patient. Erythematous mucosa simply means the inner lining of the stomach is red, a finding that points directly to inflammation. This observation is not a final diagnosis, but rather a descriptive finding that alerts doctors to an underlying issue. Subsequent investigation focuses on determining the specific irritant or condition responsible for the redness.
What the Term Means
The term “erythematous mucosa” is a medical observation indicating that the stomach lining, or mucosa, is visibly red due to increased blood flow, which is the body’s characteristic response to irritation or injury. This finding is medically synonymous with gastritis, which is defined as inflammation of the gastric mucosa. Gastritis is categorized based on its duration and appearance.
When the redness is sudden and severe, it is called acute gastritis, often presenting with a prominent infiltration of white blood cells called neutrophils in the tissue. Conversely, chronic gastritis involves long-standing inflammation, typically characterized by lymphocytes and plasma cells, which can slowly lead to thinning and damage of the protective lining over time. The distinction between acute and chronic presentation is important because it offers immediate clues about the nature of the cause, whether it is a recent exposure or a persistent condition.
The Primary Bacterial Culprit
The most common cause of chronic erythematous mucosa, or chronic gastritis, worldwide is the bacterium Helicobacter pylori (H. pylori). This spiral-shaped, Gram-negative organism has evolved to survive the highly acidic stomach environment by producing an enzyme called urease. Urease breaks down urea, creating a cloud of alkaline ammonia around the bacteria that temporarily neutralizes the stomach acid in its immediate vicinity.
Once protected, H. pylori uses its flagella to move through the thick, protective mucus layer and anchor itself directly to the stomach’s epithelial cells. This colonization triggers a continuous, low-grade inflammatory response by the host’s immune system, which is unable to fully clear the infection. This persistent inflammation is the basis of the redness seen during an endoscopy. If left untreated, this chronic inflammation can lead to complications, including peptic ulcers and an increased risk of gastric cancer.
Chemical and Environmental Irritations
Beyond bacterial infection, many non-infectious factors can damage the stomach lining, resulting in erythematous mucosa, often leading to acute gastritis. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), such as ibuprofen and aspirin, are a major cause of this chemical irritation. NSAIDs impair the stomach’s natural defense mechanisms by inhibiting the cyclooxygenase (COX) enzyme, specifically COX-1, which is responsible for producing protective prostaglandins.
Prostaglandins are molecules that play a role in maintaining the mucosal barrier by promoting the secretion of mucus and bicarbonate, and regulating blood flow to the stomach lining. When this protective layer is compromised by NSAID use, the acidic contents of the stomach can cause direct injury to the underlying cells. This damage is a primary driver of the redness and inflammation seen in drug-induced gastritis.
Excessive consumption of alcohol is another common chemical irritant that can cause erythematous changes in the stomach lining. Alcohol directly disrupts the mucosal barrier and leads to acute inflammation and superficial damage. Smoking and severe physiological stress, such as major injury or illness, can also contribute to gastritis by reducing blood flow to the mucosa or increasing acid secretion. Bile reflux is another cause, occurring when bile and pancreatic secretions flow backward from the small intestine into the stomach, chemically irritating the gastric lining.
How Doctors Pinpoint the Specific Cause
When erythematous mucosa is observed during an upper endoscopy, the medical team must perform further tests to identify the specific underlying cause, as treatment is entirely dependent on the source of the irritation. The endoscopy itself is usually the first step, allowing the doctor to visually assess the pattern and severity of the inflammation. During this procedure, a biopsy is typically taken—a small sample of the reddened tissue is collected for microscopic examination.
The biopsy is crucial for differentiating between acute and chronic inflammation and for checking for the presence of the H. pylori bacterium directly in the tissue. Other diagnostic tools are used to confirm an H. pylori infection, including non-invasive tests like the urea breath test or a stool antigen test. A detailed patient history is equally important, as information about regular medication use, especially NSAIDs, and alcohol consumption can often point to a chemical cause. Blood tests may also be utilized to check for indicators of chronic inflammation or anemia.