Risk of macrophage activation syndrome in adult-onset Still's disease patients with skin involvement: A retrospective cohort study.

Abstract Background Small case series and case reports indicated atypical persistent pruritic eruptions (PPEs), another type of skin lesions in adult-onset Still’s disease (AOSD), imply a worse prognosis than typical evanescent rashes. Objective To investigate clinical characteristics and macrophage activation syndrome (MAS) occurrence in AOSD with PPEs. Methods A retrospective cohort study analyzed 150 AOSD patients with rashes at the First Affiliated Hospital of Zhejiang University from January 2013 to December 2019. Results AOSD with PPEs had higher lactate dehydrogenase (492.00 U/L vs 382.00 U/L, p＜0.0001) and ferritin (6944.10 ng/mL vs 4286.60 ng/mL, p=0.033), and lower fibrinogen (5.05 g/L vs 5.77 g/L, p=0.014) than those with evanescent rashes. AOSD with PPEs had a higher incidence (17.4% vs 3.1%, p=0.006) and cumulative event rate for MAS (p=0.008), who tended to receive high-dose glucocorticoid (36% vs 20.3%, p=0.036). Multivariate analysis indicated PPEs (HR=5.519, 95%CI=1.138-26.767, p=0.034), aspartate aminotransferase (AST) >120 U/L (HR=8.084, 95%CI=1.728-37.826, p=0.008) and splenomegaly (HR=21.152, 95%CI=2.263-197.711, p=0.007) were independent risk factors for MAS. Limitations Single-center, retrospective nature, small sample size. Conclusion PPEs indicated increased severity and MAS occurrence than evanescent rashes. PPEs, AST >120 U/L and splenomegaly were risk factors for MAS in AOSD with skin involvement.