Etiology, classification, characteristics and differential diagnosis of various types of chronic gastritis

Causes of chronic gastritis

1. Sequelae of acute gastritis

If acute gastritis is followed by persistent or recurrent gastric mucosal lesions, chronic gastritis can develop.

2. Irritating foods and medications

Long-term consumption of foods and medications that strongly irritate the gastric mucosa, such as strong tea, strong alcohol, spicy foods, or salicylates, or insufficient chewing of food, repeated damage to the gastric mucosa from rough foods, or excessive smoking, which causes nicotine to directly affect the gastric mucosa.

3. Reflux of duodenal fluid

Studies have found that pyloric sphincter dysfunction in patients with chronic gastritis often leads to bile reflux, which may be an important pathogenic factor. Phospholipids in pancreatic juice, along with bile and pancreatic digestive enzymes, can dissolve mucus and damage the gastric mucosal barrier, promoting the backdiffusion of H⁺ and pepsin into the mucosa, further causing damage. Chronic gastritis caused by this primarily occurs in the antrum of the stomach.

4. Immune factors

Changes in immune function have been widely recognized in the pathogenesis of chronic gastritis. Parietal cell antibodies can be found in the blood, gastric juice, or atrophic mucosa of patients with atrophic gastritis, especially gastritis of the gastric body. Intrinsic factor antibodies have been found in the blood of patients with gastric atrophy and pernicious anemia, indicating that autoimmune reactions may be a related cause of some chronic gastritis.

5. Infectious factors

Studies have found a large number of Helicobacter pylori (HP) bacteria near the surface of epithelial cells in the gastric antrum mucus layer of patients with chronic gastritis, with a positive rate as high as 50% to 80%. This bacterium is not found in normal gastric mucosa. Wherever this bacterium colonizes, inflammatory cell infiltration of the gastric mucosa is observed, and the degree of inflammation is related to the number of bacteria.

Classification of chronic gastritis

Some patients find that despite undergoing gastroscopy at different hospitals and all reporting chronic gastritis, the diagnoses are often inconsistent. One hospital might diagnose it as superficial gastritis, another as erosive gastritis, while yet another might diagnose it as reflux gastritis. After visiting several hospitals, patients are often confused about their specific type of gastritis. To clarify this issue, we must begin with the classification of gastritis. Because the clinical manifestations, endoscopic findings, and gastric mucosal biopsy results of chronic gastritis can sometimes be quite inconsistent, there is currently no unified and reasonable classification standard for chronic gastritis.

Some are classified according to their etiology, such as drug-induced gastritis, alcoholic gastritis, and reflux gastritis;

It can be classified according to the morphology of the lesions, such as erosive gastritis and verrucous gastritis;

It can be classified according to the location of the lesion, such as antral gastritis and body gastritis;

Some are classified according to gastric secretion function, such as hyperacidity gastritis and hypoacidity gastritis;

Some are classified according to pathology, such as superficial gastritis and atrophic gastritis.

Currently, chronic gastritis in clinical practice includes two types: chronic superficial gastritis and chronic atrophic gastritis.

Chronic superficial gastritis includes three types: simple, erosive, and hemorrhagic, which are the most common in clinical practice.

Characteristics of various chronic gastritis

The symptoms of gastritis may vary from person to person, and many people may not even have typical symptoms.

Some common symptoms include:

1. The onset is slow, with discomfort or pain in the upper abdomen after eating. The pain is often irregular, paroxysmal, or persistent.

2. It may be accompanied by loss of appetite or anorexia, nausea, vomiting, abdominal distension and belching.

3. Symptoms may include weight loss, fatigue, diarrhea, glossitis, brittle nails, and anemia, most commonly iron-deficiency anemia.

4. During the examination, mild tenderness in the upper abdomen, pale skin and mucous membranes, smooth tongue, and little coating may be found.

Differences:

1. Superficial gastritis: decreased appetite, fullness and discomfort in the upper abdomen after meals, or a feeling of pressure, feeling better after belching, or occasional nausea, vomiting, acid reflux or pain.

2. Atrophic gastritis: loss of appetite, postprandial fullness, dull pain in the upper abdomen, as well as weight loss, anemia and diarrhea.

3. Hypertrophic gastritis: Upper abdominal pain is similar to that of peptic ulcer disease, and the pain may be temporarily relieved by eating or taking alkaline drugs. Indigestion is common, and some patients may develop gastric bleeding.

Because the pathological changes of various types of gastritis are different, their development outcomes are also different.

1. Chronic superficial gastritis: This is the most common type clinically. The gastric mucosal lesions are relatively mild, and symptoms can range from mild to severe. Severe cases may present with abdominal pain, bloating, nausea, and vomiting, while mild cases may only experience upper abdominal discomfort. Most clinical symptoms can be relieved by removing the triggering factors; only a small number of patients with significant symptoms require medication. Chronic superficial gastritis is curable, but a small percentage may develop into erosive gastritis or atrophic gastritis. Malignant transformation is generally unlikely.

2. Erosive gastritis: This is an acute inflammatory change in the gastric mucosa that often occurs on the basis of chronic superficial gastritis. It can be caused by taking medications such as aspirin, phenylbutazone, or indomethacin, or by alcoholism, shock, etc. Patients may experience bleeding or severe upper abdominal pain. With treatment with antacids or gastric mucosal protectants, most patients can be cured, but a small number may develop gastric ulcers.

3. Bile reflux gastritis: This is caused by alkaline bile flowing back into the stomach, damaging the gastric mucosal barrier. It mostly occurs in patients who have undergone partial gastrectomy and is a reversible condition; only by eliminating bile reflux can this disease be cured.

4. Atrophic gastritis: This is the most difficult type of gastritis to treat. Its incidence is age-related, increasing with age, leading some scholars to consider it a disease of the elderly. Based on the location of the lesions and the presence or absence of parietal cell antibodies, atrophic gastritis is classified into types A and B. Type A lesions occur in the gastric body and are positive for parietal cell antibodies; type B lesions are mainly in the gastric antrum and are negative for parietal cell antibodies. Type B is more common in my country. Atrophic gastritis is difficult to cure, and most patients live with the condition for life. A very small percentage may develop into gastric cancer; some statistics show that the cancer rate 10 years after developing atrophic gastritis is less than 6%.

Abdominal pain is not necessarily a sign of gastritis.

Many people know that chronic gastritis can cause abdominal pain, so they assume that any abdominal pain is a symptom of chronic gastritis. However, this is not always the case.

Abdominal pain is a common symptom, not a disease. When a patient experiences abdominal pain, their medical history, the location, timing, characteristics of the pain, and their dietary habits should be taken into account before determining whether they have chronic gastritis.

Chronic gastritis is certainly one of the most common causes of chronic upper abdominal pain. Patients experience irregular abdominal pain, often described as mild, dull, or bloating pain, which is more pronounced after meals and may be accompanied by belching, nausea, and early satiety. However, other stomach diseases, as well as diseases of the duodenum, gallbladder, and pancreas, can also cause chronic upper abdominal pain.

If a patient experiences chronic upper abdominal pain, with a small localized area, and the pain occurs before meals (hungry pain), often worsening in cold seasons, accompanied by acid reflux and heartburn, duodenal ulcer or gastric ulcer should be considered. If the patient frequently experiences significant upper abdominal pain during the course of the illness, sometimes even severe colic, accompanied by fever and jaundice, and the abdominal pain is usually related to eating fatty foods, cholecystitis or gallstones should be considered.

Some patients with functional dyspepsia experience symptoms of indigestion and chronic abdominal pain due to impaired gastric motility. Therefore, frequent upper abdominal pain can be caused by chronic gastritis, or by diseases such as gastric and duodenal ulcers, cholecystitis, gallstones, and functional dyspepsia. To make an accurate diagnosis, doctors must consider the characteristics of each disease and their own clinical experience, and may perform examinations such as gastroscopy, ultrasound, or even CT scans when necessary.

Chronic gastritis and gastric ulcer are two different diseases.

It is important to note that chronic gastritis and gastric ulcers are two different diseases, and it cannot be assumed that chronic gastritis can cause gastric ulcers.

Among chronic gastritis, superficial gastritis is the most common. Some patients may be asymptomatic, and a diagnosis can be made solely through gastroscopy. Atrophic gastritis is more common in the elderly, and a small number of these cases are accompanied by precancerous lesions. However, most people with atrophic gastritis do not need to worry about cancer developing.

There are many factors that contribute to the development of gastric ulcers. Currently, two main factors are considered: stomach acid and bacteria (Helicobacter pylori). If medication is used to suppress excessive stomach acid and Helicobacter pylori is eradicated, gastric ulcers can be cured.