Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of excessive immune system activation and inflammatory response due to a variety of primary and secondary factors that can cause a range of clinical symptoms and, in severe cases, life-threatening conditions. Patients with HLH are at increased risk of infection due to their abnormal immune function as well as chemotherapy and immunosuppressive therapy at the time of treatment. At the same time, the lack of specific clinical features makes complex infections in HLH challenging to diagnose and treat. The management of complex infections in HLH requires a multidisciplinary and integrated approach including the early identification of pathogens, the development of anti-infection protocols and regimens, and the elimination of potential infection factors. Especially in HLH patients with septic shock, empirical combination therapy against the most likely pathogens should be initiated, and appropriate anti-infective regimens should be determined based on immune status, site of infection, pathogens, and their drug resistance, with timely antibiotic adjustment by monitoring procalcitonin. In addition, anti-infection prophylaxis for HLH patients is needed to reduce the risk of infection such as prophylactic antibiotics and vaccinations. In conclusion, complex infection in HLH is a serious and challenging disease that requires vigilance, early identification, and timely anti-infective therapy.
Keywords: complex infections; differential diagnosis; hematological malignancy; hemophagocytic lymphohistiocytosis; management.