Adult-Onset Still's Disease With Suspected Steroid Hypersensitivity: A Case Report

Adult-onset Still's disease (AOSD) is a rare, systemic auto-inflammatory disorder characterised by quotidian spiking fevers, arthralgia or arthritis, and a salmon-pink maculopapular rash. Corticosteroids are the mainstay of treatment, but rarely, hypersensitivity reactions to steroids can complicate management. Here, we report a complicated case of a 39-year-old woman who presented with recurrent high-grade fever, arthralgia, rash, sore throat, and lymphadenopathy. Laboratory investigations revealed elevated inflammatory markers and serum ferritin. She met Yamaguchi criteria for AOSD and responded well to intravenous methylprednisolone, but later developed a pruritic rash suggestive of a hypersensitivity reaction. Her treatment was switched to oral prednisolone, after which her symptoms resolved and she continued to improve. This case highlights the diagnostic challenges of AOSD and the need for awareness of rare steroid hypersensitivity reactions. In patients with suspected AOSD who develop new or atypical cutaneous symptoms during steroid therapy, clinicians should consider the possibility of hypersensitivity. Early recognition and management can help achieve favourable outcomes in complex cases.