Postpartum macrophage activation syndrome with temporal dissociation of cytopenias in a patient with Kikuchi-Fujimoto disease and undifferentiated connective tissue disease: a case report.

Background: Macrophage activation syndrome (MAS) is a life-threatening hyperinflammatory disorder; postpartum MAS is extremely rare and often misdiagnosed due to overlap with sepsis and HELLP syndrome. Kikuchi-Fujimoto disease (KFD) and undifferentiated connective tissue disease (UCTD) may increase susceptibility, but reports are scarce. This case highlights the diagnostic challenges of postpartum MAS in the setting of overlapping inflammatory conditions. Case Description: The patient was a 35-year-old primiparous woman with KFD and UCTD who underwent cesarean section for preeclampsia and cervical insufficiency. She developed septic shock postoperatively. Despite infection control, persistent fever and a distinct temporal dissociation emerged: platelets recovered from 12 to 198 ×10 Conclusions: To our knowledge, postpartum MAS associated with KFD and UCTD has rarely been reported. This case demonstrates that a low or normal sCD25 level does not necessarily exclude the diagnosis of MAS. The temporal dissociation of platelet recovery preceding neutrophil decline may provide an early clue to distinguish evolving MAS from controlled infection. Prompt combination immunosuppressive therapy can be life-saving.