COVID-19 Induced Secondary Hemophagocytic Lymphohsitocytosis: A Case Series

Hemophagocytic lymphohistiocytosis (HLH) is a lethal and rapidly progressive hyper-inflammatory state that lead to development of fulminant multi-organ failure. HLH is divided into primary or familial HLH (FHL) and secondary HLH (sHLH). It can be triggered by a variety of agent that affect the immune system, infection is a common triggering agent. Recently, Coronavirus disease (COVID-19) has spread all over the world and was declared a pandemic. COVID-19 infection in children can induce serious hyper-inflammatory syndrome termed multisystem inflammatory syndrome (MIS-C). Clinically MIS-C patients present with features that resemble Kawasaki’s disease or toxic shock syndrome and the clinical and laboratory manifestations may also similar to that of secondary hemophagocytic lymphohistiocytosis, or macrophage activation syndrome (MAS). The reported HLH syndrome in children with COVID-19 increased during 2020-2021. In this case series we present two pediatric patient diagnosed as sHLH post- COVID-19 infection with a brief literature review of similar pediatric patients.