Adult-Onset Still's Disease Presenting as Aseptic Meningitis: A Case Report and Literature Review.

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disease that usually presents with nonspecific symptoms, making early diagnosis difficult. It presents with high spiking fevers, salmon-colored rashes, and arthritis. However, atypical presentations of AOSD exist, as seen in this case, where AOSD manifested as aseptic meningitis, further complicating the diagnosis. Given its rarity and symptom overlap with infections and autoimmune diseases, AOSD poses significant diagnostic challenges. This is a case report of a 51-year-old Saudi Arabian female who suffered several weeks of fever and rash and was initially treated for an allergic reaction. However, the persistence of symptoms led to further investigation. A rheumatology consultation suggested AOSD based on persistent fever, leukocytosis, and negative cerebrospinal fluid cultures. Laboratory findings, including a raised ferritin level, further supported the diagnosis. She was effectively treated with corticosteroids, immunoglobulins, and other immunosuppressive drugs, resulting in complete symptom resolution. This case highlights the importance of considering AOSD in patients with aseptic meningitis and persistent systemic inflammation, reinforcing the need for timely diagnosis and intervention.