MKSAP 19 "Quiz Me!" Question: Answer and Critique


D: Stool antigen testing for H. pylori

Educational Objective

Diagnose Helicobacter pylori infection.


The most appropriate management for this young patient with uninvestigated dyspepsia is stool antigen testing for Helicobacter pylori (Option D). In the management of dyspepsia, benefits and costs favor a test-and-treat strategy for H. pylori infection. Patients who test positive for H. pylori should receive eradication therapy. Patients negative for H. pylori on noninvasive testing are treated with empiric proton pump inhibitor (PPI) therapy. Appropriate noninvasive testing for H. pylori includes a monoclonal stool antigen test or a 13C urea breath test.

If H. pylori test results are negative or H. pylori eradication fails to relieve the dyspepsia, an empiric trial of a daily PPI (Option B) should be followed for 4 weeks. Patients whose symptoms are not alleviated with PPI therapy should undergo further evaluation with upper endoscopy.

Serologic testing (Option C), which does not discriminate between past and active H. pylori infection, should be avoided. Particularly in low-prevalence populations, such as this patient, the test has a low accuracy for identifying active infection. A positive serologic test result may lead to unnecessary treatment in a substantial number of patients because of its high false-positive rates.

This patient is young and has no alarm features for malignancy, such as anemia, family history of gastrointestinal cancer, or melena; therefore, further invasive testing with upper endoscopy (Option E) is not indicated at this time. For the same reasons, CT (Option A) would be of low yield and would not warrant the cost or radiation exposure.

Key Points

  • For patients with dyspepsia, a “test and treat” strategy for Helicobacter pylori infection is recommended.
  • In a person from an area with a low prevalence of Helicobacter pylori, a positive serologic result is likely a false positive and should be followed by a stool antigen test or a 13C urea breath test.


Moayyedi P, Lacy BE, Andrews CN, et al. ACG and CAG clinical guideline: management of dyspepsia. Am J Gastroenterol. 2017;112:988-1013. PMID: 28631728 doi:10.1038/ajg.2017.154

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