Macrophage activation syndrome complicating early course of adult-onset Still's disease

Introduction Adult-onset Still's disease is a rare inflammatory disorder of unknown etiology. It can be complicated by macrophage activation syndrome, a potentially life-threatening condition. While macrophage activation syndrome and adult-onset Still's disease share similar features, early recognition is very difficult in clinical praxis. Case outline We report a young woman, whose illness was presented suddenly, with spiking fever, sore throat, myalgia, arthralgia, and maculopapular rash. In suspicion of sepsis, she received antibiotics, despite no evidence of infection. After two weeks, her condition worsened, which was followed by cytopenia, elevated liver enzymes, and high serum levels of ferritin. She was diagnosed with macrophage activation syndrome in the early course of adult-onset Still's disease. She was treated with high doses of corticosteroids and cyclosporine A and recovered completely. Conclusion Macrophage activation syndrome can occur at the beginning of adult-onset Still's disease. Early recognition and timely administration of immunosuppressive drugs are important for the successful outcome in this condition.