What is adult Still's disease?

Systemic inflammatory disorder of unknown etiology, clinical triad (daily spiking high fevers, evanescent rash, arthritis) Biological tiad (hyperfirritinemia, hyperleukocytosis with neutrophilia, abnormal LFT) Is is a rare disorder, equal distribution between sexes, between 16-35 years old, <16 years have systemic-onset juvenile idiopathic arthritis (SOJIA)