Autoinflammation is a generally accepted pathogenic mechanism leading to systemic signs and symptoms. We report the case of a young female presenting with high-grade fever, rash, and arthralgias. After a thorough assessment, the diagnosis of adult-onset Still's disease was made based on presenting symptoms and elevated serum ferritin, c-reactive protein (CRP), and absence of serologic markers and confirmed based on Yamaguchi criteria. This evidence concerns the gene CRP and adult-onset Still disease.