Diagnosing Rheumatoid Arthritis
Diagnosing rheumatoid arthritis (RA) in the early stages can be difficult. There is no single test that can clearly identify rheumatoid arthritis. Instead, doctors diagnose rheumatoid arthritis based on factors that are strongly associated with the disease. The American College of Rheumatology uses this list of criteria:
- Morning stiffness in and around the joints for at least one hour.
- Swelling or fluid around three or more joints simultaneously.
- At least one swollen area in the wrist, hand, or finger joints.
- Arthritis involving the same joint on both sides of the body (symmetric arthritis).
- Rheumatoid nodules, which are firm lumps in the skin of people with rheumatoid arthritis. These nodules are usually in pressure points of the body, most commonly the elbows.
- Abnormal amounts of rheumatoid factor in the blood.
- X-ray changes in the hands and wrists typical of rheumatoid arthritis, with destruction of bone around the involved joints. However, these changes are typical of later-stage disease.
Rheumatoid arthritis is officially diagnosed if four or more of these seven factors are present. The first four factors must have been present for at least six weeks. More recently, guidelines have changed somewhat in an attempt to diagnose RA in its earlier stages.
Symptoms of rheumatoid arthritis can come and go but are usually persistent. To diagnose RA, your doctor may need to see your joints when the disease is active for several reasons:
- Patients may find it hard to describe symptoms to doctors in a way that allows them to make the diagnosis.
- Rheumatoid arthritis can appear similar to other common causes of joint pain, leading to the wrong diagnosis.
- Patients often think they are feeling "normal" aches and pains and ignore or just live with their symptoms for a long time before seeking treatment.
Several diseases can masquerade as rheumatoid arthritis, which contributes to the difficulty in diagnosis. These other diseases include:
- Other autoimmune diseases such as systemic lupus erythematosus (lupus)
- Joint inflammation caused by infections
Because of these difficulties, a proper diagnosis is often missed early on. In fact, the average time between the onset of symptoms and the official diagnosis of rheumatoid arthritis is almost nine months.
Though diagnosing rheumatoid arthritis isn't easy, it is extremely important to correctly identify those with the disease. Delaying the diagnosis can be harmful because joint damage can occur early in the disease. Some experts think that blocking early joint damage can have huge long-term benefits.
The problem arises when it looks like someone has rheumatoid arthritis but they don't yet meet the criteria for diagnosis. If someone doesn't actually have it, it would be wrong to treat them because the drugs used to treat RA are powerful and can have serious side effects.