Psoriatic arthritis psoriatic arthritis, and affect them symmetrically. Involvement of the spinal joints is more suggestive of psoriatic arthritis than rheumatoid arthritis. Osteoarthritis shares certain clinical features with psoriatic arthritis such as its tendency to affect multiple distal joints in an asymmetric pattern. Unlike psoriatic arthritis, osteoarthritis does not typically involve inflammation of the sacroiliac joint. Psoriatic arthritis sometimes affects only one joint and is sometimes confused for gout or pseudogout when this happens. There are five main types of psoriatic arthritis: The underlying process in psoriatic arthritis is inflammation; therefore, treatments are directed at reducing and controlling inflammation. Milder cases of
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.