Non-Classical Complications of Adult-Onset Still's Disease: A Multicenter Spanish Study

Area of Science:

• Rheumatology
• Internal Medicine
• Clinical Immunology

Background:

• Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder.
• While macrophage activation syndrome (MAS) is a known severe complication, atypical manifestations are less understood.

Purpose of the Study:

• To determine the prevalence and clinical spectrum of non-classical complications in AOSD.
• To identify factors associated with the occurrence of these atypical manifestations.

Main Methods:

• A multicenter, cross-sectional study was conducted using data from the Spanish registry on Still's disease.
• 107 patients with AOSD were analyzed for non-classical complications and associated factors.

Main Results:

• Nearly 60% of AOSD patients experienced non-classical complications, including cardiac (22.7%), pleural (28.9%), and atypical skin issues (38.8%).
• Lymphadenopathy and a higher systemic score system (SSC) index were linked to increased risk, whereas typical rash correlated with reduced risk.

Conclusions:

• AOSD involves a wide range of uncommon, potentially severe complications beyond MAS.
• Considering these atypical manifestations in patient evaluation and management is crucial for reducing morbidity and mortality.