Abstract
Macrophage activation syndrome (MAS), synonymous with secondary hemophagocytic lymphohistiocytosis (HLH), is a rare and critical complication of rheumatologic disease stemming from the unregulated activation and rapid multiplication of macrophages and T lymphocytes. While it primarily manifests in children diagnosed with systemic juvenile idiopathic arthritis (sJIA), it can arise less frequently in other rheumatologic conditions. Here, we outline the clinical course, treatment, and outcome of MAS diagnosed in an 18-year-old female previously diagnosed with SLE who exhibited a unique clinical presentation.