Differences Between Osteoarthritis and Rheumatoid Arthritis
It's important to recognize the differences between the 2 conditions to provide appropriate drug therapy.
Osteoarthritis (OA) is the most common chronic condition of the joints, affecting approximately 27 million Americans.1 Rheumatoid arthritis (RA) is the third most common type of arthritis, affecting approximately 1.3 million Americans.2
There are many similarities between OA and RA, including joint pain and inflammation. However, OA is defined as joint stiffness caused by loss of cartilage between joints due to wear and tear,1 while RA stems from an autoimmune attack on joints.3 The 2 conditions can also be differentiated by their clinical presentations.
OA usually presents asymmetrically, meaning only 1 side of the body may be affected at times. A common OA symptom is morning stiffness in joints within minutes of waking up.1
Meanwhile, RA usually presents with symmetrical joint swelling that has been persistent for a long time,3 although that isn’t always the case, especially when the condition is in early stages. Deformities of the hand can occur in severe cases of RA, causing fingers to point in different directions. RA not only affects joints, but can also cause lung inflammation that leads to shortness of breath.4
It’s important to differentiate one disease from the other for the purposes of treatment, as available treatment options for OA are different from those for RA.
The initial pharmacological treatment of RA usually involves a nonsteroidal anti-inflammatory drug (NSAID) to help reduce symptoms of pain and inflammation. Eventually, additional treatment will be needed to reduce autoimmune response. A disease modifying anti-rheumatic drug (DMARD) is a good choice for that indication, and available options include methotrexate, hydroxychloroquine, sulfasalazine, and leflunomide.5
The concomitant use of a DMARD and NSAID should help reduce RA symptoms, but if this combination therapy isn’t adequate, the addition of a biologic medication could be considered. The biologics adalimumab (Humira), etanercept (Enbrel), and tocilizumab (Actemra) are indicated for RA treatment.5 Corticosteroids like methylprednisolone can also be used to reduce inflammation while waiting for DMARDs and biologics to take effect.
When treating OA, it’s important to consider exercise as part of the regimen, as studies have shown that a simple walk around the neighborhood can help relieve pain and reduce joint stiffness.1 Weight loss can also play a critical role in reducing OA symptoms because it can ease pressure on joints, which reduces frictional rubbing of bones.
Analgesics like acetaminophen and NSAIDs can be used to help resolve OA-related pain. Topical capsaicin can be used as an alternative or addition to drug therapy, as a review of randomized, controlled trials found that it’s efficacious compared with placebo for knee OA and reduces pain by 50%.6
Corticosteroid injections can be used to help reduce pain and inflammation temporarily, but biologics aren’t used for OA because the condition doesn’t involve an autoimmune attack on joints. In general, appropriate diet considerations and exercise can help reduce the severity of OA.
RA and OA are prevalent in many individuals, and as our population ages, the number of those affected will continue to increase. Therefore, it’s important to recognize the differences between the 2 conditions to provide appropriate drug therapy.
1. Arthritis Foundation. Osteoarthritis. arthritis.org/about-arthritis/types/osteoarthritis/ Accessed June 10, 2016.
2. American College of Rheumatology. Prevalence statistics. rheumatology.org/Learning-Center/Statistics/Prevalence-Statistics. Accessed June 10, 2016.
3. Ruffing V, Bingham CO III. Rheumatoid arthritis signs and symptoms. hopkinsarthritis.org/arthritis-info/rheumatoid-arthritis/ra-symptoms/ Updated January 13, 2016. Accessed June 11, 2016.
4. Arthritis Foundation. Rheumatoid arthritis. arthritis.org/about-arthritis/types/rheumatoid-arthritis/ Accessed June 10, 2016.
5. Singh JA, Saag KG, Bridges L JR, et al. 2015 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res (Hoboken). 2016 Jan;68(1):1-25. doi: 10.1002/acr.22783. Epub 2015 Nov 6.
6. Yu SP, Hunter DJ. Managing osteoarthritis. Aust Prescr. 2015;38(4):115-119. doi:10.18773/austprescr.2015.039.