Acute Immune Thrombocytopenia Following Influenza Vaccination in a Patient With Untreated Helicobacter pylori Infection

A 70-year-old man with previously normal comprehensive blood counts (CBCs) was referred to our hospital for acute thrombocytopenia. Following a negative workup for secondary causes, we diagnosed immune thrombocytopenia (ITP). Aside from the influenza vaccine administered six days before presentation, there was no discernable precipitant on history. His only risk factor for ITP was untreated Helicobacter pylori diagnosed over two months prior. With treatment, the patient's platelets normalized within three days. ITP following influenza vaccination has been documented in the literature and reported to regulatory bodies. Our case indicates that individuals with untreated H. pylori infection might be particularly vulnerable to such occurrences.