Hemophagocytic Lymphohistiocytosis in Children

Hemophagocytic lymphohistiocytosis (HLH) is a disorder of the immune regulatory system with a high rate of mortality. The clinical presentation of HLH could be similar to those of many other conditions, making its diagnosis difficult. The current study was conducted on the children with HLH referred to the Pediatric Ward of Imam Reza Hospital, Mashhad, Iran during nine years from 2010 to 2018. The data collection tool included items on clinical presentations, physical examination, laboratory data, treatment strategy, and the disease outcome. The diagnosis of HLH was made based on the HLH-2004 Diagnostic Criteria. Data were analyzed using SPSS version 20. Among the 17 cases with HLH, the mean age at the onset of HLH was 4.671 ± 4.60 years with a male to female ratio of 11:6. Fever and splenomegaly were the most common findings. The study of the etiology revealed that about 30% of the children had the familial form of HLH, 17.5% were previously diagnosed with rheumatologic disorders (i.e., systemic lupus erythematosus and systemic-onset juvenile idiopathic arthritis), and the same rate was affected by infectious diseases. Idiopathic factors, the Chediak-Higashi syndrome, and the Griscelli syndrome were responsible for the occurrence of HLH in 17.5%, 12%, and 6% of the cases, respectively. According to the obtained results of the study, 35.3% of the patients were cured and about 64.7% died. Due to the high risk of mortality from this disorder, the recognition of HLH symptoms, especially atypical presentations of the disorder, is critical both for pediatricians and subspecialists.