The word ARTHRITIS originates from the Ancient Greek and translates as “joint inflammation”. Both osteoarthritis (OA) and Rheumatoid arthritis (RA) are characterized by joint inflammation. Inflammation is recognized by the presence of pain, heat, swelling, redness and loss of function. So, what are the differences in these two painful joint conditions?
The first difference lies in the cause of the disease. RA is an autoimmune disease, meaning that the body’s own immune system attacks itself (specifically targeting the joints). Why the body’s immune system starts to attack itself is not fully understood. It may be due to an interaction between the body’s genetic code and the environment, for example a virus may spark off inflammation in the joints. Autoimmune diseases are more common in women and often occur in people with other autoimmune diseases, for example, thyroid disease. Those with a family history of autoimmune diseases are also at greater risk of this disease. OA, in contrast, is a degenerative disease, meaning that is a result of “wear and tear” of the cartilage in the joint and is therefore associated with older age, injury to the joints and obesity. However, similarly to RA, OA is also more common in women and there is a strong genetic risk, particularly in OA of the hands.
The distribution of joints that are affected differ between OA and RA. In OA, the distribution tends not to be symmetrical. The hips, knees, and the small joints of the hands can be affected. RA is usually symmetrical and affects the small joints of the hands, particularly the wrists and knuckles and also the feet. Both conditions can lead to characteristic deformities. For example, bony overgrowths develop in OA, known as osteophytes. These are often in the end joints of the fingers and appear as bony swellings. In RA, the deformities can be severe and disabling, if the disease is not well controlled by medication.
With regards to symptoms, both conditions may result in joint pain, swelling, stiffness and reduced range of movement. However, OA pain is made worse by movement and therefore tends to be more severe at the end of the day. Based on this, a diagnosis of OA can be made if the patient is over the age of 45 years , has activity-related joint pain and if morning joint stiffness (if there is any) lasts less than 30 minutes. In contrast, RA pain and stiffness may last more than one hour in the morning and is alleviated by movement. RA is a systemic disease, meaning that other parts of the body can be affected, such as the eyes or the lungs. OA is always isolated to the joints.
OA and RA have their own individual and specific x-ray changes. Due to the immunological origin of RA, blood tests can be used to indicate the inflammatory process. Blood tests in OA are normal.
The treatment of these diseases differ as a result of their different causes. OA is managed using pain killers, both topical (applied directly to the painful area) and by mouth. Steroid injections into the joint can also aid in relieving the symptoms. Physiotherapy, in particular muscle building exercises, is very important. Sometimes, a joint replacement may be necessary if the condition is no longer responding to these treatments. RA also requires pain killers, however “remission” is achieved by using oral steroids initially to dampen down the immune attack on the joints. In addition, drugs known as Disease Modifying Anti-Rheumatic Drugs (DMARDs) are used to control the disease process and maintain remission. Examples of these include methotrexate, leflunomide and sulfasalazine. For severe cases, biological treatment, such as anti-TNF, may be useful.
The recognition of key differences between OA and RA enables appropriate and therefore effective management aimed at reducing suffering and improving quality of life.