Adult-Onset Still's Disease in a 49-Year-Old Female in the UAE: A Case Report and Literature Review.

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disorder characterized by high spiking fevers, salmon-colored rash, arthritis, and hyperferritinemia. It often mimics infections or autoimmune conditions, leading to diagnostic delays. We report a case of a 49-year-old female who presented with fever, fatigue, arthralgia, evanescent rash, and elevated inflammatory markers. Extensive infectious and autoimmune workups were negative. Her serum ferritin exceeded 16,000 ng/mL. She fulfilled the Yamaguchi criteria for AOSD, and treatment with corticosteroids followed by tocilizumab resulted in marked clinical improvement. This is, to our knowledge, the first documented case of AOSD from the UAE. It underscores the importance of ferritin in diagnosis and disease monitoring and highlights the efficacy of interleukin (IL)-6 inhibition in management.