An Unusual Presentation of Adult-Onset Still's Disease as Hemophagocytic Lymphohistiocytosis in a Male Patient.

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and potentially fatal condition characterized by immune activation and multi-organ dysfunction. HLH can be inherited in an autosomal recessive fashion, but can also be secondary to infections, malignancy, immunosuppression, and autoimmune conditions. Adult-onset Still's disease (AOSD) is an autoimmune disorder that can predispose patients to HLH.