1. Mainly arthritis: such AS rheumatoid arthritis (RA), Still's disease is divided into juvenile and adult types, ankylosing spondylitis (AS) and psoriatic arthritis. 2. Infection-related: rheumatic fever, Lyme disease, Wright syndrome and reactive arthritis. 3. Diffuse connective tissue disease: systemic lupus erythematosus (SLE), primary Sjogren's syndrome (pSS), systemic sclerosis (SSc), polymyositis (PM), dermatomyositis (DM), mixed connective tissue disease (MCTD) and vasculitis.