A Never Ending Case of Helicobacter pylori

Question: A 55-year-old woman was originally referred to our practice for evaluation of persistent abdominal pain and nausea. Prior to her presentation, the patient was found to have Helicobacter pylori (H pylori) on stool antigen testing by her primary care provider. The patient had a past medical history significant for an anaphylactic allergy to penicillin and thus her initial course of triple therapy consisted of clarithromycin, metronidazole and lansoprazole. Despite appropriate therapy, her symptoms persisted and therefore an esophagogastroduodenoscopy (EGD) was performed. Findings from her EGD demonstrated multiple pre-pyloric ulcers with biopsies consistent with H pylori. Given her notable allergy to penicillin, amoxicillin was avoided as she underwent multiple rounds of therapy (Table 1) with no improvement in her symptoms. Throughout her therapeutic course, the patient was periodically called to confirm she was compliant with her prescribed treatment.Table 1Therapy Regimes for Helicobacter pyloriRegimen 1: Clarithromycin, metronidazole, and lansoprazoleRegimen 2: Tetracycline, metronidazole, dexlansoprazole, and bismuth subsalicylateRegimen 3: Clarithromycin, metronidazole, and dexlansoprazoleRegimen 4: Levofloxacin, tetracycline, dexlansoprazole, and bismuth subsalicylateRegimen 5: Levofloxacin, nitazoxanide, doxycycline, and dexlansoprazole Open table in a new tab The patient was subsequently lost to follow up for a few years until returning with the same symptoms. Repeat EGD and biopsies remained positive for H pylori. She thereafter underwent H pylori culture and sensitivity analysis with testing revealing susceptibilities to amoxicillin, ciprofloxacin, metronidazole, tetracycline and a resistance to clarithromycin. At this point, expert gastrointestinal consultation was sought from a quaternary center and the patient was treated with omeprazole, metronidazole, tetracycline and bismuth subsalicylate. Despite treatment, her symptoms continued and biopsy testing remained positive for H pylori. What is the next most appropriate step?A.Refer the patient for penicillin allergy testing.B.High dose dual regimen with amoxicillin.C.Rifabutin based therapy.D.Obtain additional sensitivities. Look on page 1553 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image(s) to Practical Teaching Cases. The correct answer is A. The patient was referred for penicillin allergy testing and successfully passed skin and oral amoxicillin challenges. The patient was then treated with high dose dual therapy with amoxicillin 750 mg four times a day and rabeprazole 20 mg four times a day with symptomatic improvement and eradication of H pylori based on repeat EGD biopsy results. Answer B is incorrect as the patient’s allergy could have truly been anaphylactic therefore warranting allergy testing in order to proceed safely. Answer C is incolrrect as rifabutin based therapy includes amoxicillin as well. Answer D is incorrect as the patient had failed eradication attempts multiple times and warranted allergen testing H pylori is a common cause of peptic ulcer disease and known risk factor for gastric cancer. First line therapy for the treatment of H pylori consists of quadruple therapy, but when eradication is unsuccessful, it is often due to antibiotic resistance. In such cases, antibiotic susceptibility testing is recommended to limit the use of unnecessary antibiotics.1Fallone C.A. Moss S.F. Malfertheiner P. Reconciliation of recent Helicobacter pylori Treatment Guidelines in a Time of Increasing Resistance to antibiotics.Gastroenterology. 2019; 157: 44-55Abstract Full Text Full Text PDF PubMed Scopus (135) Google Scholar Amoxicillin is an important component of first line and salvage regimens used in the treatment of H pylori. In patients with a reported penicillin allergy who fail treatment with regimens that avoid amoxicillin, it is important to consider allergy testing given that many do not have a true penicillin allergy. Nearly 10% of the general population report an allergy to penicillin making it the most common reported drug allergy in the United States which has led to the public health issue of “penicillin avoidance.” However, of all the patients with a reported allergy, 90% of these patients are found not to be allergic to penicillin after skin testing.2Gonzalez-Estrada A. Radojicic C. Penicillin allergy: a practical guide for clinicians.Cleve Clin J Med. 2015; 82: 295-300Crossref PubMed Scopus (43) Google Scholar Despite this, penicillin avoidance remains a significant public health issue in the United States. For the definitive management of our patient, we chose high dose dual therapy with a PPI and amoxicillin. Such a regimen has been demonstrated to be an effective strategy for salvage therapy and it avoids any potential issue of clarithromycin resistance.3Yang J.C. Lin C.J. Wang H.L. et al.High-dose dual therapy is superior to standard first-line or rescue therapy for Helicobacter pylori infection.Clin gastroenterol Hepatol. 2015; 13: 895-905Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar In conclusion, in patients with a reported penicillin allergy who fail H pylori eradication using regimens avoiding amoxicillin, it is important to consider penicillin allergen testing. By identifying patients who are not truly allergic, we can prevent the use of broad-spectrum regimens and help prevent the development of multi-drug resistant pathogens. CME Exam 2: A Never Ending Case of Helicobacter pyloriGastroenterologyVol. 158Issue 6Preview Full-Text PDF