The differential diagnosis of fever, polyarthritis, and an evanescent, salmon-pink maculopapular rash includes infection, autoimmune conditions, and malignancy. However, adult-onset Still’s disease (AOSD) should be considered when laboratory studies show neutrophilic leukocytosis, elevated inflammatory markers, and marked hyperferritinemia. Clinicians should know AOSD is considered to be on the same spectrum as systemic juvenile idiopathic arthritis, both of which are now simply classified as Still’s disease. Even though Still’s disease is a diagnosis of exclusion, delay in diagnosis can come at a cost — up to 15% of patients with AOSD carry the risk of developing macrophage activation syndrome.
Comment
The differential diagnosis of fever, polyarthritis, and an evanescent, salmon-pink maculopapular rash includes infection, autoimmune conditions, and malignancy. However, adult-onset Still’s disease (AOSD) should be considered when laboratory studies show neutrophilic leukocytosis, elevated inflammatory markers, and marked hyperferritinemia. Clinicians should know AOSD is considered to be on the same spectrum as systemic juvenile idiopathic arthritis, both of which are now simply classified as Still’s disease. Even though Still’s disease is a diagnosis of exclusion, delay in diagnosis can come at a cost — up to 15% of patients with AOSD carry the risk of developing macrophage activation syndrome.