From Fever to Arthralgia: Unraveling Adult-Onset Still's Disease in Adults. A Case Report

Systemic disorder of unknown etiology, characterized by arthritis, fever, transient rash, and other systemic presentations. We report a case of AOSD with history of high-grade fever, joint pains and clinical examination, which revealed the characteristic Salmon-pink evanescent rash is seen in AOSD, which could have been easily missed as it disappears when fever subsides, and its diagnosis was supported by very high levels of serum ferritin, and we confirmed the diagnosis by fulfilling the Yamaguchi criteria after excluding the other possible diagnoses. She showed a partial response to prednisolone but later was advised to take methotrexate, which resulted in further alleviation of her residual symptoms. Conclusion: Every Fever doesn’t carry an infectious etiology; try to think outside of the box and careful history and examination and in turn, supported by the pertinent investigations, can lead to solve these sorts of enigmatic cases as was done in our case Keywords: Adult-onset still’s disease, AOSD, Arthritis, Evanescent rash, Prednisolone, Yamaguchi criteria