Influenza-Associated Hemophagocytic Syndrome in Adults: Case Report and Review

Hemophagocytic syndrome (HPS) is a rare, but increasingly reported disease characterized by severe dysfunction of cytotoxic T cells and NK cells, often associated with poor outcome. It has been related to multiple processes including a large variety of infections. Even though viral infections have been described as triggers of HPS, influenza associated hemophagocytic syndrome in adults has been rarely reported. Here, we present a case of an 85 year-old man with essential thrombocytemia who developed HPS triggered by influenza A H1N1 infection and a review of the literature with special emphasis on the importance of a prompt diagnosis and an early treatment to achieve a more favourable outcome. Hemophagocytic syndrome secondary to influenza virus infection is a rare condition with high mortality that should be suspected in patients with an aggressive disease course. Early diagnosis and initiation of antiviral treatment and in some cases immunomodulatory therapy are crucial for the prognosis.