Hemophagocytic Lymphohistiocytosis Secondary to Mycoplasma pneumoniae Infection without Pneumonia

Mycoplasma pneumoniae typically causes respiratory tract infections, including pneumonia. We herein report the case of a 30-year-old Japanese woman with hemophagocytic lymphohistiocytosis (HLH), which is rarely caused by bacteria, secondary to Mycoplasma pneumoniae infection and ensuing hypercytokinemia without pneumonia who was successfully treated with a combination of antibiotics and corticosteroids. Therefore, Mycoplasma pneumoniae infection, which is treatable with antibiotics, should be considered a possible trigger of HLH in patients who present with a viral-like illness without pneumonia.