Hemophagocytic Lymphohistiocytosis-like syndrome following rotavirus infection in a pediatric patient with severe pneumonia: a case report and literature review.

Background: Hemophagocytic syndrome (HPS), also known as hemophagocytic lymphohistiocytosis (HLH), is characterized by persistent fever, cytopenias, hepatosplenomegaly, and elevation of typical HLH biomarkers, often associated with a high mortality rate. Secondary HLH is frequently triggered by infections, with viral HLH being the most common infectious etiology in children. Although various viruses have been implicated in the induction of HLH, reports of HLH triggered by rotavirus infection are scarce, primarily occurring in post-transplantation immunosuppressed patients. The condition has a poor prognosis and is associated with a high mortality rate.

Case presentation: This study presents a case of a 4-year-old boy, previously healthy and not in an immunosuppressed state, who developed HLH symptoms following rotavirus infection. Genetic testing revealed no HLH-related mutations. Initially, the patient presented with severe pneumonia and a suspected lung abscess. After receiving anti-infective treatment, the pneumonia improved. During the stable recovery phase, the child developed vomiting, diarrhea, and recurrent fever. Stool tests were positive for human rotavirus antigen. Despite symptomatic treatment, the fever persisted and worsened, accompanied by abdominal pain, rash, neutropenia, hyperferritinemia, hypofibrinogenemia, hypertriglyceridemia, and liver dysfunction. Bone marrow biopsy revealed phagocytic activity, leading to a strong clinical suspicion of HLH. The patient was subsequently treated with corticosteroids and supportive therapy. The child responded rapidly, with symptom resolution, normalization of inflammatory and hematologic markers, and a favorable outcome.

Conclusion: This case highlights a rare but critical presentation of hemophagocytic syndrome-like symptoms triggered by rotavirus infection in a non-immunocompromised child. Given the high mortality associated with HLH, especially when triggered by common viral infections, clinicians should maintain a high index of suspicion and initiate early intervention when compatible symptoms arise.