10% of a Single center cohort (n 38) Systemic JIA pts developed MAS. Only1 had recurrent MAS(3 times), mostly Male (3M:1F) w/ mean Dx age=8 ± 6 yrs. Stills w/ MAS had less arthritis (51 v 91%), more Rash (75 v 55%), HSM (50 v 5%), serositis (25 v 5%) https://t.co/QgdSJW03wj https://t.co/L5MTnmgWDn