Adult-onset Still's Disease

Adult-onset Still's disease (AOSD) is a rare auto inflammatory condition characterized by high fever, joint pain, a transient salmon-colored rash, and elevated ferritin levels. Its diagnosis is primarily clinical, relying on the exclusion of infections, malignancies, and other autoimmune disorders. A 23-year-old woman presented with intermittent high fever, polyarthralgia, and a fleeting salmon-pink rash. Laboratory results showed neutrophilic leukocytosis, elevated ESR, CRP, and ferritin (1650 ng/mL), along with mild liver enzyme elevation and negative ANA/RF tests. Extensive investigations for infections and cancer were inconclusive. She met the Yamaguchi criteria for Adult-onset Still's disease. The patient responded well to oral prednisolone and methotrexate. After a relapse at 7 months, treatment was adjusted with increased methotrexate doses, a short course of steroids, and NSAIDs. At a one-year follow-up, she remains symptom-free, with normalized ferritin levels (280 ng/mL) and no signs of macrophage activation syndrome (MAS). Adult-onset Still's disease should be considered in patients with fever of unknown origin accompanied by systemic inflammation. Early recognition and immunosuppressive therapy can lead to remission, even in settings with limited resources.