Helicobacter pylori infection

Helicobacter pylori infection

Helicobacter pylori infection

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H. pylori - The Stomach Squatter

  • Gram-negative, spiral-shaped bacterium that colonizes the gastric mucosa.
  • Produces urease, which hydrolyzes urea into $NH_3$ and $CO_2$ to neutralize local acid.
  • Transmission: Fecal-oral or oral-oral routes.

Clinical Associations:

  • Chronic gastritis & Peptic Ulcer Disease (PUD), especially duodenal ulcers.
  • Gastric Adenocarcinoma & MALT Lymphoma.

H. pylori in gastric pit, histopathology

Diagnosis & Management:

  • Tests: Urea breath test, stool antigen, or endoscopy with biopsy.
  • Treatment:
    • 📌 CAP regimen: Clarithromycin + Amoxicillin + PPI.
    • Quadruple Therapy for resistance: Bismuth + Metronidazole + Tetracycline + PPI.

⭐ H. pylori is the only bacterium classified as a Class I carcinogen, directly linked to gastric cancer.

Clinical Features - Gut Feelings

  • Majority Asymptomatic: Most individuals are carriers without symptoms.
  • Chronic Gastritis: The most common clinical outcome.
    • Epigastric pain (burning, gnawing), often worse at night or with an empty stomach.
    • Nausea, bloating, and early satiety.
  • Peptic Ulcer Disease (PUD):
    • Duodenal Ulcer: Pain classically improves with meals.
    • Gastric Ulcer: Pain classically worsens with meals.
  • Alarm Features: Unintentional weight loss, persistent vomiting, dysphagia, melena/hematemesis, or iron deficiency anemia (IDA).

H. pylori infection is the strongest known risk factor for gastric MALT lymphoma; successful eradication therapy leads to lymphoma regression in ~75% of cases.

Endoscopic view of peptic ulcers

Diagnosis - The Great Detective

  • Initial Approach: Choice of test depends on indication for endoscopy.
  • Non-Invasive Tests:
    • Urea Breath Test (UBT) & Stool Antigen: High sensitivity/specificity for active infection. Used for initial diagnosis and to confirm eradication.
    • Serology (IgG): Shows exposure, not active disease. 📌 Stays positive after eradication.

Test-Modifying Meds: Stop PPIs for 2 weeks and antibiotics/bismuth for 4 weeks before UBT or stool antigen testing to avoid false negatives.

Treatment - Eviction Notice

  • Goal: Eradicate H. pylori to heal peptic ulcers, treat MALT lymphoma, and reduce gastric cancer risk.

  • First-Line Therapy (10-14 days):

    • Bismuth Quadruple: PPI + Bismuth + Metronidazole + Tetracycline.
      • Preferred if clarithromycin resistance is high or patient had macrolide exposure.
      • 📌 Please Make Tummy Better (PPI, Metro, Tetra, Bismuth).
    • Clarithromycin Triple: PPI + Clarithromycin + Amoxicillin.
      • Use only if local clarithromycin resistance is <15%.
      • Use Metronidazole for Amoxicillin if penicillin allergy.
  • Salvage Therapy: If first-line fails, use an alternative regimen (e.g., Levofloxacin-based).

⭐ Confirm eradication with urea breath test or fecal antigen test >4 weeks after ending antibiotics and >2 weeks after stopping PPIs to prevent false negatives.

  • H. pylori is a gram-negative, spiral-shaped bacterium strongly associated with peptic ulcer disease (PUD), especially duodenal ulcers.
  • It is a major risk factor for gastric adenocarcinoma and MALT lymphoma.
  • Urea breath test and stool antigen testing are the preferred non-invasive diagnostic methods.
  • Standard treatment is triple therapy: a Proton Pump Inhibitor (PPI), clarithromycin, and amoxicillin.
  • Always confirm eradication with a urea breath or stool antigen test >4 weeks after completing therapy.

Practice Questions: Helicobacter pylori infection

Test your understanding with these related questions

A 45-year-old woman has a history of mild epigastric pain, which seems to have gotten worse over the last month. Her pain is most severe several hours after a meal and is somewhat relieved with over-the-counter antacids. The patient denies abnormal tastes in her mouth or radiating pain. She does not take any other over-the-counter medications. She denies bleeding, anemia, or unexplained weight loss, and denies a family history of gastrointestinal malignancy. Which of the following is the best next step in the management of this patient?

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Flashcards: Helicobacter pylori infection

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Gastric ulcers are usually due to _____ (~ 70%)

TAP TO REVEAL ANSWER

Gastric ulcers are usually due to _____ (~ 70%)

H. pylori

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