Gastritis is a medical condition characterized by the inflammation or erosion of the lining of the stomach. It is characterized by gastric mucosal damage represented by inflammation processes, degenerative metaplasia, allergic processes.
Gastritis comes in two forms and they are:
* Acute Gastritis
It involves the superficial erosion of the gastric mucosa. With acute gastritis, it is self- limiting. Regeneration of the mucosa occurs within 24 to 72 hours.
* Chronic Gastritis
With chronic gastritis there is prolonged and repeated irritation of the mucosa. It results in progressive, irreversible atrophy of the gastric mucosa and glands. It occurs in three forms; * Superficial gastritis: It causes reddened oedematous mucosa with haemorrhage and small erosion. * Atrophic gastritis: This occurs in all three layers of the stomach and is characterized by a decreased number of parietal and chief cells. * Hypertrophic gastritis: Causes a dull and nodular mucosa with irregular thickening rugae. There are two main classification; * TYPE A (Fundal): It results from parietal cell changes leading to atrophy and cellular infiltration. It may be triggered by psycho-emotional stresses. * TYPE B (Antral): It occurs in the antrum and is usually due to degenerative changes and colonization of the mucosa by bacteria. Example is the Helicobacter pylori.
With chronic gastritis the causes are the same as the acute form. When acute gastritis is not treated, it progresses into the chronic form.
Acute Gastritis: This is mostly caused by excessive alcohol consumption and smoking especially on an empty stomach. Potassium and iron supplements, chronic ingestion of irritating food or allergic foods (example mushroom, hot spices, shellfish etc), ingestion of corrosive poison like lead, mercury are also associated with gastritis. Prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin also causes acute gastritis.
Gastritis may also develop after major surgery, traumatic injury, burns, or severe infections. Gastritis usually occurs in those who have had weight loss surgery resulting in the reconstruction of the digestive tract.
Chronic Gastritis: This is caused by infection most especially Helicobacter pylori; endotoxins released from infecting bacteria such as streptococci, staphylococci; certain diseases such as Crohn's disease; pernicious anemia; chronic bile reflux; stress; excessive radiation use; chemotherapy and some autoimmune disorders.
Mucous gland metaplasia could also cause this form of Gastritis.
The stomach’s rich blood supply, mucous layer, and acidic environment provide a formidable barrier to localized infections, and the digestive substances it secretes normally HCL and pepsin. The pathogenesis of gastritis however, is multifactorial and results from an imbalance of the aggressive gastric luminal factors, acid and pepsin, and defensive mucosal barrier functions of the mucus and bicarbonate. Infections of a type of bacteria called Helicobacter pylori colonize the deep layers of gastric mucosa and weaken its defense system by reducing the thickness of the mucosal layer and diminishing mucosal blood flow. This results in the development of gastritis in infected individuals.
Mucous gland metaplasia (a reversible replacement of differentiated cells) occurs in the setting of severe damage of the gastric glands, which then waste away (atrophic gastritis). Intestinal metaplasia (complete or incomplete) typically begins in response to chronic mucosal injury in the antrum, and...