Complications

Most complications from adult Still's disease arise from chronic inflammation of organs and joints.

• Joint destruction. Chronic inflammation can damage your joints. The most commonly involved joints are your knees and wrists. Your neck, foot, finger and hip joints also may be affected, but much less frequently.
• Inflammation of your heart. Adult Still's disease can lead to an inflammation of the saclike covering of your heart (pericarditis) or of the muscular portion of your heart (myocarditis).
• Excess fluid around your lungs. Inflammation may cause fluid to build up around your lungs, which can make it hard to breathe deeply.
• Macrophage activation syndrome. This rare, but potentially fatal complication of adult Still's disease, can cause low blood cell counts, very high triglyceride levels and abnormal liver function.