Clinical presentation
| Clinical manifestations | Comments |
| Asymptomatic | Majority of children. The infection should not be investigated. |
| Digestive manifestations | |
| Nausea | Meta-analysis showed significant association between nausea and and Helicobacter pylori infection.12 The infection should not be investigated. |
| Epigastric pain | Meta-analysis documented statistical significant association.13 Other studies do not find predominance of this symptom in infected cases. It is a common indication of OEGD. |
| Chronic abdominal pain without any alarm signs or symptoms | The pain is probably independent of the presence of H. pylori. The infection should not be investigated or treated. |
| Vomiting | Meta-analysis showed no direct link between infection and vomiting.13 |
| Heartburn, halitosis, regurgitation | Non-specific symptom. It does not constitute indication of study or treatment. |
| Extradigestive manifestations | |
| Unexplained iron deficiency anaemia | After other causes have been ruled out, the infection should be investigated. |
| Chronic immune thrombocytopenic purpura | Unexplained thrombocytopenia should undergo H. pylori testing. Eradication and therapy have shown promising results with improved platelet counts and the normalisation of autoplatelet antibodies without relapse. |
| Henoch-Schonlein purpura | More research are needed to asociate H. pylori infection with abdominal manifestations and also to define the need for eradication therapy. |
| Inflammatory bowel disease | Meta-analysis suggests strong inverse association with Crohn’s disease in children.16 17 |
| Bronchial asthma, other allergic diseases | Meta-analysis showed an inverse relationship. More research is needed.18 |
EGD, oesophago-gastro-duodenoscopy.