Arthritis Australia and run community seminars. Arthritis is an umbrella term for more than 100 medical conditions that affect the musculoskeletal system, specifically joints where two or more bones meet. The three most significant – osteoarthritis, rheumatoid arthritis and gout – account for more than 95 per cent of cases in Australia. The most common forms of arthritis are: Arthritis-related problems include pain, stiffness, inflammation and damage to joint cartilage (the tissue that covers the ends of bones, enabling them to move against each another) and surrounding structures. This can result in joint weakness, instability and deformities that can interfere with the
HLA-B spondyloarthropathies, a group of disorders that includes ankylosing spondylitis and other inflammatory joint diseases. Some of these diseases are associated with a common skin condition called psoriasis or chronic inflammatory bowel disorders (Crohn's disease and ulcerative colitis). One of the spondyloarthropathies, reactive arthritis, is typically triggered by bacterial infections of the gastrointestinal or genital tract. Following an infection, affected individuals may develop arthritis, back pain, and eye inflammation. Like ankylosing spondylitis, many factors probably contribute to the development of reactive arthritis and other spondyloarthropathies. Other disorders: Several variations of the HLA-B gene are associated with adverse reactions to certain drugs.