Great question, Linda. Even we rheumatologists often have trouble distinguishing the two. Osteoarthritis is thought of as a wearing away of cartilage with aging, which in the long terms can result in need for joint replacement due to chronic pain. Although there may be a little inflammation in the joints, this is not a big component of the disease. Psoriatic arthritis, on the other hand, is an inflammatory condition in which the joints become inflamed and damaged as a result of inflammation. It is usually associated with psoriasis, a scaly skin condition that can range from one or two patches to diffuse involvement of the body. The treatments for the two conditions are very different, so a correct diagnosis if key. Usually there is not too much trouble telling the apart, but sometimes because both cause bone spurs, they can look somewhat similar.
About Joan Bathon, M.D.
Dr. Bathon was a Co-Deputy Director of the Division of Rheumatology at Hopkins Bayview. She was also the founder and director of the Hopkins Arthritis Center.