流感疫苗接種後血小板減少症之案例報告

Immune Thrombocytopenia after Influenza Vaccination: A Case Report

流感疫苗接種是年度公衛重要政策，接種前需做身體評估及詢問過敏史以避免不良反應發生。個案為79歲男性，接種流感疫苗後第五天口腔黏膜出現血泡、流鼻血、血便及紫斑，經檢查後診斷為免疫性血小板低下症，後續治療後出血症狀改善出院；一週後因發燒、呼吸喘、A型流感快篩陽性，診斷為肺炎再次住院治療。流感疫苗接種後之血小板低下案例相當罕見，且無法區分何者為高危險族群，建議接種前評估應多注意相關不良反應記錄，尤其是出血、紫斑或過敏，並加強衛教與施打前評估，以降低風險及促進病人安全。

Influenza vaccination is one of the main public health interventions to prevent influenza. Prior to vaccination, doctors should inform patients with a history of allergy about adverse drug reactions. We report the case of a 79-year-old man who presented with oral mucosal and nasal bleeding 5 days after receiving the flu vaccine and was subsequently diagnosed with immune thrombocytopenia. His symptoms improved and platelet count recovered after treatment with prednisolone and eltrombopag. Immune thrombocytopenia related to vaccination is rare. Due caution should be exercised before administering influenza vaccine to patients with thrombocytopenia or myelodysplastic syndrome-related hematologic diseases. Vaccine-related thrombocytopenia typically occurs within 2-3 weeks of vaccination. Patients with a history of thrombocytopenia should be informed about the related risks before vaccination.