Definition, Classification and Etiology of Gastritis

• The term gastritis should be reserved for histologically documented inflammation of the

gastric mucosa.

• Gastritis is not the mucosal erythema seen during endoscopy and is not interchangeable

with ‘dyspepsia.’

• The etiologic factors leading to gastritis are broad and heterogeneous.



Classification and Aetiology

• Gastritis has been classified based on time course

Acute

Chronic

Acute Gastritis

• This is a term covering a broad spectrum of entities that induce inflammatory changes in the gastric mucosa.

• The different aetiologies share the same general clinical presentation. However, they

differ in their unique histological characteristics.

• The inflammation may involve the entire stomach (e.g. pan gastritis) or a region of the

stomach (e.g. antral gastritis).

Types of Acute Gastritis

• Acute gastritis can be broken down into 2 categories

Erosive (eg, superficial erosions, deep erosions, hemorrhagic erosions)

Non-erosive (generally caused by Helicobacter pylori)

• The most common causes of acute gastritis are infectious

• Acute infection with H. pylori induces gastritis

• Other infection include

Helicobacter helmanni

Phlegmonous

Mycobacterial

Syphilitic

Viral

Parasitic

Fungal

• Other causes of acute gastritis

NSAIDS

Alcohol

Drugs-Iron

Bile

 Severe psychological stress

Uremia

Clinical Features of Acute Gastritis

• Reported as presenting with sudden onset of

Epigastric pain

Nausea

Vomiting

• If not treated, this picture will evolve into one of chronic gastritis.

• The highly acidic gastric environment may be one reason why infectious processes of the

stomachs are rare.

• Bacterial infection of the stomach or Phlegmonous gastritis is a rare potentially life-threatening

disorder, characterized by marked and diffuse acute inflammatory infiltrates

of the entire gastric wall, at times accompanied by necrosis. Elderly individuals,

alcoholics and AIDS patients may be affected.

• Other types of infectious gastritis may occur in immunocompromised individuals such as

AIDS patients. Examples include herpetic (herpes simplex) or CMV gastritis.

 

Chronic Gastritis

• Chronic gastritis is identified histologically by an inflammatory cell infiltrate consisting

primarily of lymphocytes and plasma cells, with very scant neutrophil involvement.

• This form of gastritis increases with age.

• Chronic gastritis may progress into gastric atrophy with subsequent metaplasia, this may

ultimately lead to the development of gastric adenocarcinoma

• H. pylori infection is now considered an independent risk factor for gastric cancer.

• Infection with H. pylori is also associated with the development of a low-grade B cell

lymphoma, Gastric MALT (mucosa-associated lymphoid tissue) lymphoma.

Differential Diagnosis Of Acute Gastritis

• Peptic ulcer

• Oesophagitis

• Gastric carcinoma

• Dyspepsia

Investigations Of Gastritis

• Most of the specific investigations are performed at the hospital level and therefore referring

the patient for the relevant investigation will be necessary. The investigations are outlined

below.

• The number of laboratory tests is usually ordered.

CBC count to assess for anemia, as acute gastritis can cause gastrointestinal bleeding

Liver and kidney function tests

Gallbladder and pancreatic function tests

• Stool for occult blood

• Imaging Studies: barium meal

• Procedures: endoscopy

Treatment of Gastritis

• Most of the treatment options may be not available at dispensary and health center level

and therefore referral maybe unavoidable. Administer medical therapy as needed,

depending on the cause and the pathological findings.

• No specific therapy exists for acute gastritis, except for cases caused by H pylori.

• Administer fluids and electrolytes as required, particularly if the patient is vomiting.

• Discontinue the use of drugs known to cause gastritis (e.g. NSAIDs, alcohol).

• No effective antiviral therapy exists for the treatment of human cytomegalovirus

(HCMV) infection, though 2 agents (i.e. ganciclovir, foscarnet) be

virostatic.

• The treatment of Candida albicans includes a variety of agents, including nystatin, oral

clotrimazole, itraconazole, fluconazole, amphotericin B, and ketoconazole.

• Triple therapy, with indicated adult dose (eradication of H. pylori) for 14 days then

continue acid suppression to complete 4-8 weeks.

Proton pump inhibitors (PPI) - Lansoprazole 30 mg PO once a day or Omeprazole 20

mg PO once a day for 4 – 8 weeks

Clarithromycin 500 mg PO bid or Amoxicillin 500 mg PO 8 hourly for 1 week

plus metronidazole 400mg PO 8 hourly for 1 week

Treatment of Chronic Gastritis

• Treatment in chronic gastritis is aimed at the sequelae and not the underlying

inflammation.

• Patients with pernicious anemia will require parenteral vitamin B12 supplementation on

a long-term basis.

• Eradication of H. pylori is not routinely recommended unless PUD or a low-grade

lymphoma is present.

REFERENCES;

•      Braunwald & Fauci (2001). Harrison’s principles of internal medicine 15th Ed.  Oxford: McGraw Hill

•      Davidson, S (2006). Principles and practice of medicine 20th Ed.  Churchill: Livingstone.

Kumar & Clark (2003) Textbook of clinical medicine. Churchill: Livingstone.

•      Douglas Model (2006): Making sense of Clinical Examination of the Adult patient. 1st Ed. Hodder Arnold