Symptoms of psoriatic arthritis
Like psoriasis, psoriatic arthritis is a chronic disease that grows more severe over time. It may develop slowly, or the symptoms may come on suddenly. There may be periods of remission when symptoms improve that alternate with periods of time when the symptoms of psoriatic arthritis become worse.
Like other types of arthritis, psoriatic arthritis causes the joints to become swollen and very painful. Similar to rheumatoid arthritis, psoriatic arthritis also causes joints to become warm to the touch. Psoriatic arthritis sometimes affects only the joints on one side of the body, but it can affect both sides. Other signs and symptoms that distinguish psoriatic arthritis from other types of inflammatory arthritic conditions include:
- Significant swelling in the toes and fingers: The sausage-like swelling of psoriatic arthritis in the toes and fingers is especially severe and painful. The feet and hands may become deformed before joint symptoms occur.
- Foot pain: Psoriatic arthritis causes severe pain at the back of the heel where ligaments and tendons join the bone or on the bottom of the foot.
- Low back pain: A condition called spondylitis sometimes results from psoriatic arthritis. This causes pain and inflammation in the spine joints and in the joints between the pelvis and spine.
When to see a doctor
Psoriatic arthritis can cause severe damage to the joints if it is not treated. If you have psoriasis and you develop joint pain, be sure to notify your doctor.
Psoriatic arthritis diagnosis
A diagnosis of psoriatic arthritis is based on the patient’s history, their family history, and a physical examination that includes carefully examining the joints for signs of tenderness and swelling. The physician will also check the fingernails for evidence of flaking and examine the feet and heels for tenderness and swelling.
There is no one test to confirm psoriatic arthritis diagnosis, but there are tests that can rule out conditions with similar symptoms, such as gout or rheumatoid arthritis.
- X-rays: Certain changes occur in the joints with psoriatic arthritis that do not occur in other forms of arthritis. X-rays can help detect these changes.
- Magnetic resonance imaging (MRI): An MRI uses a powerful magnetic field and radio waves to produce images with great details of the hard as well as soft tissues of the body. It can detect ligament and tendon problems that often occur in the feet and lower back of patients with psoriatic arthritis.
- Rheumatoid factor (RF): This is a test that helps the doctor rule out a condition with symptoms similar to psoriatic arthritis. RF is an antibody that people with rheumatoid arthritis often carry in their blood. It typically is not present in the blood of people with psoriatic arthritis diagnosis.
- Joint fluid analysis: This test helps rule out gout as a cause of pain and inflammation in the joints. A sample of joint fluid is taken from an affected joint by withdrawing it through a long needle. It is analyzed in the lab for the presence of uric acid crystals. These crystals are usually present in cases of gout rather than in psoriatic arthritis.