Background: Uncontrolled phagocytosis of normal hemopoietic cells by activated histiocytes in bone marrow is collectively referred to as hemophagocytic lymphohistiocytosis.
Case: We present a case of hemophagocytic lymphohistiocytosis associated with herpes simplex virus-2 infection in the second trimester. Cytopenia, elevated C-reactive protein, ferritin, soluble interleukin-2 receptor, and interleukin-6 with high-grade fever were observed following genital herpes infection, and the existence of hemophagocytes in bone marrow confirmed the diagnosis of hemophagocytic lymphohistiocytosis. Corticosteroid therapy failed to arrest the hemophagocytic process, whereas cyclosporin A was effective. The patient delivered a healthy infant after remission and has not experienced exacerbation.
Conclusion: It is often important to take into consideration hemophagocytic lymphohistiocytosis when encountering cytopenia with high-grade fever. Cyclosporin A was a safe and available strategy for this corticosteroid-resistant case.