Adult-onset Still's disease: current challenges and future prospects.

Adult-onset Still's disease (AOSD) - a multi-systemic inflammatory condition characterized by high fevers, polyarthritis, an evanescent rash, and pharyngitis - has been a challenging condition to diagnose expediently and treat effectively. Questions remain regarding the underlying pathophysiology and etiology of AOSD. Pathognomonic diagnostic tests and reliable biomarkers remain undiscovered. Over the past decade, important progress has been made. Diagnostic criteria employing glycosylated ferritin have improved specificity. More important, novel biologic therapies have offered important clues to AOSD's underlying pathophysiology. Cytokine-specific biologic therapies have been instrumental in providing more effective treatment for disease refractory to conventional treatment. While IL-1 therapy has demonstrated efficacy in refractory disease, novel therapies targeting IL-6 and IL-18 show great promise and are currently under investigation.