Rheumatoid arthritis (RA) and osteoarthritis (OA) are two common types of arthritis, but they have different causes, clinical manifestations, and treatments. Here’s a breakdown of their clinical differences:
- Etiology:
- RA: It is an autoimmune disease. The immune system mistakenly attacks the synovium (lining of the membranes that surround the joints), leading to inflammation and eventual joint damage.
- OA: Often referred to as ‘wear and tear’ arthritis, it’s primarily a degenerative joint disease. Over time, the cartilage that cushions the ends of bones within the joint deteriorates, leading to joint damage.
- Affected Joints:
- RA: Typically affects joints symmetrically (both sides of the body). Commonly involves small joints of the hands, wrists, and feet, but can affect larger joints as well.
- OA: Commonly affects weight-bearing joints like the hips, knees, and spine. Can also affect the fingers, thumb, neck, and large toe. Typically does not occur symmetrically.
- Joint Appearance:
- RA: Joints may appear red and swollen, DIPJ spared
- OA: Joints may enlarge or develop bony knobs, called Heberden’s or Bouchard’s nodes, on the fingers.
- Pain and Stiffness:
- Both have morning stiffness but OA resolves rapidly with movement
- RA: Pain and stiffness tend to be worse in the morning or after periods of inactivity, often lasting more than an hour.
- OA: Stiffness typically occurs after periods of inactivity (like sleeping) but usually resolves within 30 minutes but then gets worse with overuse.
- Systemic Symptoms:
- RA: Can be associated with systemic symptoms like fatigue, weight loss, and low-grade fever. Some patients may develop rheumatoid nodules, lung involvement, or other extra-articular manifestations.
- OA: Primarily localized to the affected joint, without systemic symptoms.
- Age of Onset:
- RA: Can occur at any age, but it’s more common in middle age.
- OA: More common in older adults, usually over the age of 50.
- Disease Progression:
- RA: Symptoms and joint damage can progress rapidly without appropriate treatment.
- OA: Progression is usually slower, over years or decades.
- Lab and Imaging:
- RA: Blood tests often show the presence of rheumatoid factor (RF) or anti-citrullinated protein antibodies (anti-CCP). Joint X-rays, MRI, or ultrasound may show joint erosion.
- OA: Blood tests are generally not helpful in the diagnosis. X-rays show narrowing of the joint space, bone spurs, subchondral sclerosis and bone cysts
- Treatment:
- RA: Focuses on controlling the immune response. Disease-modifying antirheumatic drugs (DMARDs) such as methotrexate are commonly used. Biological agents targeting specific parts of the immune response may also be prescribed.
- OA: Treatment focuses on pain control and maintaining joint function. Includes paracetamol, NSAIDs, physiotherapy, weight management, and in severe cases, joint replacement surgery.