Types of Rheumatoid Arthritis
Rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation of the joints. Because many symptoms of RA are similar to those of a variety of other diseases, diagnosis can be difficult. A correct diagnosis requires clinical evaluation, X-rays, and a series of laboratory tests.
Understanding the type of RA you have will help you and your doctor decide on a course of treatment. Click through the slides to learn about the different types of RA.
Rheumatoid Factor Positive (Seropositive) RA
If your blood tests positive for the protein called rheumatoid factor (RF), it means your body may be actively producing an immune reaction to your normal tissues. According to the Physicians Desk Reference, your chance of developing RA is four times greater if you have first-degree relatives who test positive for RF.
According to Johns Hopkins Medicine, approximately 80 percent of people who have RA are RH-positive. Having the protein doesn't necessarily mean you have RA. However, if you do, it can help doctors identify the type.
Rheumatoid Factor Negative (Seronegative) RA
People who test negative for RF in the blood can still have RA. Diagnosis isn’t based on just this test. Your doctor will also take into account clinical symptoms, X-rays, and other laboratory tests. Although your doctor can't say for certain, people who test RF negative tend to have a milder form of RA than those who test positive.
Juvenile RA (Juvenile Idiopathic Arthritis)
The Mayo Clinic reports that juvenile RA is the most common type of arthritis in children under age 16. Symptoms may be temporary or last for a lifetime. Like adult RA, symptoms of juvenile RA include joint inflammation, stiffness, and pain. If the disease is severe, it can cause eye inflammation and interfere with a child's growth and development.
Ankylosing spondylitis is chronic inflammation of the joints of the spine that can also affect nearby structures of the vertebrae. People with this form of arthritis usually test negative for RF.
Some people experience repeated flare-ups and remissions, while others have progressive worsening of their condition. In the most severe cases, bones in the spine can fuse together, making it impossible to stand up straight, hold your head up, and decrease lung function.
Cervical Spondylotic Myelopathy (Spinal Cord Compression)
This type of RA is similar to ankylosing spondylitis, but primarily affects the neck. Cervical spondylotic myelopathy usually progresses at a slow, steady rate. However, in some patients, it progresses more quickly. Cervical spondylotic myelopathy can occur at any age, but is usually diagnosed in people over age 50.
Polymyalgia rheumatica involves pain and stiffness in the hips, shoulders, and neck. It generally develops gradually, but in some cases can come on quite suddenly. Symptoms are more prominent in the morning or after a period of inactivity and usually last more than a half hour. People younger than 50 are seldom diagnosed with this form of RA.
Overlapping and Often Confused Conditions
Autoimmune diseases share many common symptoms, making them particularly difficult to diagnose. People who have one autoimmune disorder often develop another. Some overlapping and often confused conditions include:
- Lyme disease
- chronic fatigue syndrome
RA can also be confused with osteoarthritis, which is not an autoimmune disease, but is caused by wear and tear of joints.