Peptic disease and Helicobacter pylori — formative SAQs

SAQ 1 (10)

An 11-year-old girl presents with three months of epigastric pain that sometimes wakes her at night, and one episode of black stool. Her father had a duodenal ulcer. She is growing normally but looks slightly pale. [1] [10]

1. State which alarm features are present and how they change your investigation plan. (3) [1]
2. Explain why you would not use a non-invasive test-and-treat strategy for H. pylori in this child. (3) [1] [2]
3. Outline how you would diagnose H. pylori at endoscopy and what tissue you would send. (4) [1] [5]

Model answer

Alarm features and plan. Nocturnal pain, a possible gastrointestinal bleed (melaena), pallor suggesting anaemia, and a first-degree family history of ulcer are all alarm features. Their presence moves this child to prompt upper gastrointestinal endoscopy with biopsy rather than empiric treatment or reassurance, alongside a full blood count and iron studies. [1] [10]

Why not test-and-treat. In children, unlike adults, a non-invasive test-and-treat strategy is explicitly not recommended. Most infected children never ulcerate, so a positive breath or stool test does not establish that H. pylori is causing the symptoms. Committing a child to antibiotics on a non-invasive test risks over-treatment, misses the true diagnosis, and forgoes susceptibility information. [1] [2]

Endoscopic diagnosis and tissue. Upper endoscopy allows direct visualisation of an ulcer and gastritis. Take antral and corpus biopsies for histology and a rapid urease test, and send tissue for culture and antibiotic susceptibility testing or molecular resistance testing. A reliable diagnosis needs a positive culture, or positive histology plus a positive rapid urease test, so a single false-positive does not commit the child to treatment. [1] [5]

SAQ 2 (10)

A 13-year-old boy has an endoscopically confirmed H. pylori-associated duodenal ulcer. Susceptibility testing shows a clarithromycin-susceptible strain. [1] [5]

1. Outline your eradication approach and its duration, without inventing specific doses. (4) [1] [5]
2. Explain how and when you would confirm that eradication has succeeded. (3) [1] [8]
3. State two common causes of eradication failure and how you would manage a confirmed failure. (3) [5] [1]

Model answer

Eradication approach. Use a susceptibility-guided regimen for 14 days. With a clarithromycin-susceptible strain, a proton-pump inhibitor combined with amoxicillin and clarithromycin at weight-appropriate paediatric doses is appropriate; where clarithromycin resistance is present or unknown, a bismuth-based quadruple regimen is preferred. A high-dose, weight-appropriate PPI and the full 14-day duration maximise cure, and adherence counselling is essential. Follow local paediatric dosing tables rather than unverified doses. [1] [5]

Confirming eradication. Test for cure non-invasively with a urea breath test or a monoclonal stool antigen test, performed at least four weeks after finishing antibiotics and after stopping the proton-pump inhibitor for two weeks, so that suppressed but living organisms are not missed and a false-negative avoided. Serology is not used because antibodies persist after clearance. [1] [8]

Failure causes and management. Common causes are poor adherence and antibiotic resistance, particularly to clarithromycin or metronidazole. For a confirmed failure, repeat endoscopy with fresh culture and susceptibility testing, select a tailored second-line regimen guided by those results, and reinforce adherence. Empirically cycling antibiotics without susceptibility data drives further resistance. [5] [1]