Stomach - Gastritis

The Stomach

What is Gastritis?  An inflammation, irritation or erosion

of the stomach lining. Can be of acute or a chronic complaint.  Acute gastritis often due to chemical injury (alcohol/drugs)  Chronic gastritis: H. Pylori infection, chemical, autoimmune.

What Causes Gastritis?

 Bile reflux Drugs

NSAIDs, such as aspirin, ibuprofen, and naproxen Cocaine Iron Colchicine, when at toxic levels, as in patients with failing renal or hepatic function  Kayexalate  Chemotherapeutic agents, such as mitomycin C, 5fluoro-2-deoxyuridine, and floxuridine    

 Potent alcoholic beverages, such as whisky, vodka,

and gin  Bacterial infections

 H pylori (most frequent)  H heilmanii (rare)  Streptococci (rare)

 Viral infections (eg, CMV)

Fungal infections Candidiasis Histoplasmosis Phycomycosis Parasitic infection (eg, anisakidosis) Acute stress (shock) Radiation Allergy and food poisoning Spicy food Smoking Bile: The reflux of bile (an alkaline medium important for the activation of digestive enzymes in the small intestine) from the small intestine to the stomach can induce gastritis.  Ischemia: This term is used to refer to damage induced by decreased blood supply to the stomach. This rare etiology is due to the rich blood supply to the stomach.  Direct trauma           

Acute  Acute gastritis is a term covering a

broad spectrum of entities that induce inflammatory changes in the gastric mucosa.  The different etiologies share the same

general clinical presentation. However, they differ in their unique histologic characteristics.  The inflammation may involve the

entire stomach (eg, pangastritis) or a region of the stomach (eg, antral gastritis). 

Acute gastritis can be broken down into 2 categories: erosive (eg, superficial erosions, deep erosions, hemorrhagic erosions) and nonerosive

Erosive Gastritis  Acute erosive gastritis can result from the

exposure to a variety of agents or factors. This is referred to as reactive gastritis.  These agents/factors include nonsteroidal anti-inflammatory medications (NSAIDs), alcohol, cocaine, stress, radiation, bile reflux, and ischemia.  The gastric mucosa exhibits hemorrhages, erosions, and ulcers. NSAIDs, such as aspirin, ibuprofen, and naproxen, are the most common agents associated with acute erosive gastritis.  This results from oral or systemic administration of these agents either in therapeutic doses or in supratherapeutic

Chronic The ABC in chronic Gastritis:  A – Autoimmune  B – Bacterial (H. Pylori)  C – Chemical (NSAIDs)  Chronic noninfectious granulomatous gastritis  Lymphocytic gastritis  Eosinophilic gastritis  Ischemic gastritis  Radiation gastritis

Autoimmune Gastritis  

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This type of gastritis is associated with serum antiparietal and anti-intrinsic factor (IF) antibodies. The gastric corpus undergoes progressive atrophy, IF deficiency occurs, and patients may develop pernicious anemia. Autoantibodies are directed against at least 3 antigens, including IF, cytoplasmic (microsomal-canalicular), and plasma membrane antigens. Two types of IF antibodies are detected, ie, types I and II. Type I IF antibodies block the IF-cobalamin binding site, thus preventing the uptake of vitamin B-12. Cell-mediated immunity also contributes to the disease. T-cell lymphocytes infiltrate the gastric mucosa and contribute to epithelial cell destruction and resulting gastric

H. pylori 

The corkscrew-shaped bacterium called H pylori is the most common cause of gastritis.

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Complications result from a chronic infection rather than from an acute infection.

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The prevalence of H pylori in otherwise healthy individuals varies depending on age, socioeconomic class, and country of origin.

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In the Western world, the number of people infected with H pylori increases with age.

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Evidence of H pylori infection can be found in 20% of individuals younger than 40 years and in 50% of individuals older than 60 years.

 H pylori gastritis typically starts as an acute gastritis in the antrum, causing intense inflammation, and over time, it may extend to involve the entire gastric mucosa resulting in chronic gastritis.

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Tuberculosis is a rare cause of gastritis, but an increasing number of cases have developed because of patients who are immunocompromised. Gastritis caused by tuberculosis is generally associated with pulmonary or disseminated disease. Secondary syphilis of the stomach is a rare cause of gastritis. Phlegmonous gastritis is an uncommon form of gastritis caused by numerous bacterial agents, including streptococci, staphylococci, Proteus species, Clostridium species, and Escherichia coli. Viral infections can cause gastritis. Cytomegalovirus (CMV) is a common viral cause of gastritis. It is usually encountered in individuals who are immunocompromised, including those with cancer, immunosuppression, transplants, and AIDS. Gastric involvement can be localized or diffuse. Fungal infections that cause gastritis include Candida albicans and histoplasmosis. The common predisposing factor is immunosuppression. C albicans rarely involves the gastric mucosa. Parasitic infections are rare causes of gastritis. Anisakidosis is caused by a nematode that embeds itself in the gastric mucosa along the greater curvature. Anisakidosis is acquired by eating contaminated sushi and other types of contaminated raw fish. It often causes severe abdominal pain that subsides within a few days. This nematode infection is associated with gastric fold swelling, erosions, and ulcers. Ulcero-hemorrhagic gastritis is most commonly seen in patients who are critically ill. Ulcero-hemorrhagic gastritis is believed to be secondary to ischemia related to hypotension and shock or to the release of vasoconstrictive substances, but the etiology is often unknown. Microscopic evidence of acute gastritis can be seen in patients with

Chemical Gastritis   

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This type of gastritis is associated with long-term intake of aspirin or NSAIDs. It also develops when bile-containing intestinal contents reflux into the stomach. Although bile reflux may occur in the intact stomach, most of the features associated with bile reflux are typically found in patients with partial gastrectomy, in whom the lesions develop near the surgical stoma. The mechanisms through which bile alters the gastric epithelium involve the effect of several bile constituents. Both lysolecithin and bile acids can disrupt the gastric mucous barrier, allowing the back diffusion of positive hydrogen ions and resulting in cellular injury. Pancreatic juice enhances epithelial injury in addition to bile acids. In contrast to other chronic gastropathies, minimal inflammation of the gastric mucosa typically occurs in chemical gastropathy.

Chronic noninfectious granulomatous gastritis  Noninfectious diseases are the usual

cause of gastric granulomas and include Crohn disease, sarcoidosis, and isolated granulomatous gastritis.  Crohn disease demonstrates gastric involvement in approximately 33% of the cases. Granulomas have also been described in association with gastric malignancies, including carcinoma and malignant lymphoma.  Sarcoidlike granulomas may be observed in people who use cocaine, and foreign material is occasionally observed in the granuloma.

Lymphocytic/ Eosinophilic Gastritis  Lymphocytic gastritis

 This is a type of chronic gastritis with dense

infiltration of the surface and foveolar epithelium by T lymphocytes and associated chronic infiltrates in the lamina propria.

 Eosinophilic gastritis  Large numbers of eosinophils may be observed

with parasitic infections such as those caused by Eustoma rotundatum and anisakiasis.  Eosinophilic gastritis can be part of the spectrum of eosinophilic gastroenteritis. Although the gastric antrum is commonly affected, this condition can affect any segment of the GI tract and can be segmental. Patients frequently have peripheral blood eosinophilia..

Radiation/ Ischemic Gastritis  Radiation gastritis

 Small doses of radiation (up to 1500 R) cause

reversible mucosal damage, whereas higher radiation doses cause irreversible damage with atrophy and ischemic-related ulceration. Reversible changes consist of degenerative changes in epithelial cells and nonspecific chronic inflammatory infiltrate in the lamina propria.  Higher amounts of radiation cause permanent mucosal damage, with atrophy of fundic glands, mucosal erosions, and capillary hemorrhage. Associated submucosal endarteritis results in mucosal ischemia and secondary ulcer development.

 Ischemic gastritis  Ischemic gastritis is believed to result from

atherosclerotic thrombi arising from the celiac and superior mesenteric arteries.

What are the symptoms? Vomiting

Thirst Nausea

Bloating Indigestion Pain in Epigastric Region

...symptoms  Gastrointestinal bleeding  Hemoptysis  Melena  Diarrhea  Chest Pain (associated with

indigestion)  Unpleasant taste in mouth  Apetite

How do we diagnose?  A doctor suspects gastritis when a        

person has upper abdominal discomfort or pain or nausea. Blood tests Liver, Kidney, Gallbladder and Pancreas functions Urinalysis/stool sample X-ray/ECG Nasogastric Intubation ENDOSCOPY Capsule Endoscopy Laparoscopy

Endoscopy

Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope).

 Endoscope is passed through the

mouth, to the stomach, examining the lining of the stomach  Many endoscopes are equipped with a small clipper with which tissue samples can be taken (endoscopic biopsy)  Endoscopes can also be used for treatment.

Capsule Endoscopy  Capsule endoscopy is a

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procedure in which the person swallows a battery-powered capsule. The capsule contains one or two small cameras, a light, and a transmitter. Images of the lining of the intestines are transmitted to a receiver worn on the person's belt or in a cloth pouch. Thousands of pictures are taken. This technology is especially good at finding problems on the inner surface of the small intestine, which is an area that is difficult to evaluate with an endoscope.

Nasogastric Tube Intubation of the digestive tract is the process of passing a small, flexible plastic tube (nasogastric tube) through the nose or mouth into the stomach or small intestine.  This procedure may be used for diagnostic or treatment purposes.  Nasogastric intubation can be used to obtain a sample of stomach fluid.  This determines whether the stomach contains blood, or they can analyze the stomach's secretions 

The tube is passed through the nose rather than through the mouth, primarily because the tube can be more easily guided to the oesophagus. Also, passage of a tube through the nose is less irritating and less likely to trigger coughing.