Peptic Duodenitis

Inflammation of the duodenal mucosa (usually the bulb) caused by acid and pepsin, with erythema, erosions and neutrophilic infiltration; it lies on the spectrum of duodenal ulcer disease and is often accompanied by gastric metaplasia in the duodenal bulb.

• Causes: Helicobacter pylori (antral gastritis with high acid output, found in 60 to 90%), NSAIDs and aspirin, hypersecretory states (Zollinger-Ellison syndrome), smoking, alcohol, stress, and less commonly Crohn disease, coeliac disease, giardiasis, hookworm and strongyloidiasis, cytomegalovirus, sarcoidosis, and radiation.
• Frequency: duodenal erythema or erosions are found in about 5 to 15% of dyspeptic patients at endoscopy.
• Mechanism: acid load and impaired bicarbonate secretion overwhelm duodenal defences; gastric metaplasia becomes colonised by H. pylori, causing inflammation and erosion.

Epigastric burning pain, often occurring 2 to 5 hours after meals, at night, or when hungry, relieved by food or antacids; nausea, bloating, belching, early satiety.

• Dark stools or haematemesis with bleeding erosions; weight loss and diarrhoea with coeliac disease, giardiasis or parasitic causes.
• Examination: epigastric tenderness; pallor with anaemia.
• Differential diagnosis: duodenal ulcer, gastric ulcer, gastritis, functional dyspepsia, coeliac disease, giardiasis, hookworm and strongyloidiasis, Crohn disease, pancreatitis, biliary disease, gastro-oesophageal reflux, gastric cancer.
• Complications: bleeding, duodenal ulcer, bulb scarring and outlet obstruction, perforation (rare), and iron deficiency anaemia.

Upper endoscopy: duodenal bulb erythema, oedema, erosions, nodularity, friability; biopsy the duodenum (bulb and second part) for neutrophils, gastric metaplasia, villous atrophy and increased intraepithelial lymphocytes (25 or more per 100 enterocytes suggests coeliac disease), granulomas, Giardia, and cytomegalovirus inclusions.

• Helicobacter pylori testing: gastric biopsies, urea breath test or stool antigen (off proton pump inhibitors for 2 weeks and antibiotics for 4 weeks).
• Tissue transglutaminase IgA with total IgA (and duodenal biopsy), stool microscopy or antigen for Giardia, stool examination for ova and larvae (Strongyloides serology), full blood count and ferritin, faecal calprotectin.
• Fasting serum gastrin (off proton pump inhibitors for 1 to 2 weeks if safe; more than 1000 pg/mL with gastric pH less than 2 strongly suggests Zollinger-Ellison syndrome) when there are multiple or refractory ulcers, diarrhoea, or ulcers beyond the bulb.
• NSAID history and drug review.

Acid suppression: omeprazole 20 to 40 mg daily for 4 to 8 weeks (taken 30 minutes before breakfast); famotidine 40 mg at night (20 mg if creatinine clearance is below 50 mL/min) as an alternative or for night symptoms; alginate-antacid 10 to 20 mL after meals and at bedtime for relief.

• Remove causes: stop NSAIDs (use paracetamol), stop smoking and alcohol; continue low-dose aspirin 75 mg daily only if needed for secondary prevention, with omeprazole 20 mg daily.
• Helicobacter pylori eradication when positive, for 14 days:
  • Omeprazole 20 mg twice daily, amoxicillin 1 g twice daily and clarithromycin 500 mg twice daily (where clarithromycin resistance is less than 15%).
  • Omeprazole 20 mg twice daily, bismuth subsalicylate 524 mg four times daily, tetracycline 500 mg four times daily and metronidazole 500 mg three to four times daily (first choice where resistance is high, and in penicillin allergy).
  • Test of cure at least 4 weeks after antibiotics and 2 weeks off the proton pump inhibitor.
• Mucosal protection (evidence limited): sucralfate 1 g four times daily on an empty stomach for 4 weeks (separate from other drugs by 2 hours; avoid in renal failure).
• Specific causes:
  • Giardiasis: tinidazole 2 g once, or metronidazole 400 mg three times daily for 5 days (children 15 mg/kg/day in 3 doses for 5 days).
  • Hookworm: albendazole 400 mg once (repeat in 2 weeks if heavy infection), with iron replacement.
  • Strongyloidiasis: ivermectin 200 micrograms/kg orally once daily for 2 days (repeat after 2 weeks in hyperinfection or immunosuppression).
  • Coeliac disease: lifelong gluten free diet with dietitian support, and correction of iron, folate, B12, calcium and vitamin D deficiency.
  • Crohn disease: specialist treatment with prednisolone 40 mg daily tapered over 6 to 8 weeks or biologic therapy.
  • Cytomegalovirus in immunosuppression: ganciclovir 5 mg/kg IV every 12 hours for 2 to 3 weeks.
  • Zollinger-Ellison syndrome: omeprazole 60 mg daily (titrated to acid output, up to 120 mg daily in divided doses) with localisation and surgery for resectable tumours; endocrine review for multiple endocrine neoplasia type 1.
• Bleeding: omeprazole 80 mg IV bolus then 8 mg/hour for 72 hours, resuscitation, endoscopic therapy within 24 hours, transfusion at 70 g/L (80 g/L in cardiovascular disease).
• Special groups: children (omeprazole 1 mg/kg daily, maximum 40 mg; treat H. pylori with weight-based amoxicillin 25 mg/kg twice daily and clarithromycin 7.5 mg/kg twice daily with omeprazole 1 mg/kg twice daily for 14 days); pregnancy (alginate-antacids, famotidine 20 mg twice daily, omeprazole 20 mg daily; defer H. pylori treatment; avoid albendazole in the first trimester); elderly (stop NSAIDs, consider endoscopy); renal impairment (reduce famotidine and ganciclovir doses); immunosuppression (look for opportunistic infection).
• Red flags: haematemesis or melaena, persistent vomiting, weight loss, chronic diarrhoea, severe anaemia, ulcers beyond the bulb, no response in 8 weeks.
• Follow-up: review at 4 to 8 weeks; test of cure for H. pylori; repeat endoscopy for non-response, ulcers beyond the bulb or alarm features; gastrin and coeliac testing for refractory disease; yearly review of NSAID or aspirin gastroprotection.