Unlike other forms of arthritis, psoriatic arthritis (PsA) may be accompanied by typical psoriasis symptoms, such as a red, scaly rash that will develop silvery white patches. Areas frequently affected by PsA are the hands, fingers, feet, large joints of the lower body, and the lower back.
PsA is a chronic condition that worsens over time without treatment and intervention. This condition may cause permanent damage to joints and tissues if not treated promptly.
Early diagnosis through use of imaging tests is key to preventing PsA from worsening rapidly.
What types of radiology are used?
If a doctor thinks that someone has PsA, there are a number of potential radiology options they may use to make the diagnosis.
Each test reveals different views of the disease and may help the doctor to know how far along the disease has progressed, what sort of damage has been done, and potentially help determine the best course of treatment.
Radiography uses X-rays to diagnose PsA and may be best used to detect advanced PsA.
Image credit: Dr Alexandra Stanislavsky, Radiopaedia.org. From the case rID: 12379
Radiography is the traditional means for doctors to assess and keep track of PsA. Radiography typically uses X-rays to examine the inside of the body.
Radiography is often used as one of the first means of detection. This is because an X-ray will always provide the same information to a range of different doctors and because they are relatively low-cost compared with other more advanced radiology equipment.
However, in its initial stages, PsA starts with soft tissue inflammation instead of bone and joint damage. This means that the radiography may not pick up any early signs of PsA as the bones will still appear as normal.
In more advanced stages of PsA, radiography results may show the bending of bones, particularly in the hands.
Sometimes a person has psoriasis or a family history of the disease in addition to arthritis symptoms, but the radiography shows no signs of PsA. If this occurs, a doctor may order more advanced imaging to determine if the arthritic symptoms are a result of PsA.
Magnetic resonance imaging (MRI)
MRI uses a strong magnetic field combined with radio waves to produce a very detailed image of both soft and hard tissues in the person's body.
A doctor may use this type of imaging test to check for problems with the tendons and ligaments, especially in the lower back and feet. Unlike radiography, the MRI is more likely to pick up earlier signs of PsA.
Ultrasound, a type of imaging through sound waves, has been widely used to diagnose PsA. Doctors can use ultrasound to see abnormalities in patients with the condition.
Using ultrasound, doctors can spot symptoms of arthritis in patients with skin psoriasis even before the symptoms of arthritis are even visible.
PsA shares many of the same signs and symptoms as rheumatoid arthritis, reactive arthritis, and gout. These diseases are similar in that they all cause joint pain, swelling, and a sensation of warmth to the touch.
Before diagnosing PsA, doctors need to rule out other forms of arthritis as the cause of the joint pain and swelling, and they use visual examinations, a review of medical history and laboratory tests to do this.
Laboratory tests are often used alongside imaging tests. These laboratory tests include ANA and anti-CCP antibody tests, which indicate the presence of certain antibodies. The presence of these antibodies may help point to PsA as the cause of symptoms, but it is important to know that there are no laboratory tests that can determine the presence of PsA completely.
Results gained from laboratory testing may be helpful when used in combination with a medical review and radiographic images.
A visual examination by a healthcare professional may be one of the first steps in diagnosing PsA.
A visual examination is one of the first steps in diagnosing PsA. There are several visual signs that can help a doctor decide whether a person has PsA or another form of arthritis.
For example, PsA is often, though not always, accompanied by skin lesions consistent with psoriasis. Other symptoms of PsA include color changes in the finger or toenails.
Another visual clue is that rheumatoid arthritis typically causes bumps to appear under the skin and also affects the same joints on either side of the body. Neither of these are symptoms associated with PsA.
However, a visual examination is not enough to completely rule out other forms of arthritis and a doctor should also use imaging technologies to help make a diagnosis.
Who should get checked?
PsA can affect anyone, at any age. It develops most frequently in young adults. However, both children and older people can develop the disease as well.
People with psoriasis or a family history of psoriasis are far more likely to develop PsA and should be aware of the disease's signs and symptoms.
A person who develops symptoms of arthritis and has either psoriasis or a family history of the disease should be sure to talk to their doctor about the possibility that the symptoms might be caused by PsA.
Unfortunately, there is no known cure for PsA. Once a doctor has determined that someone has PsA, they will focus their treatment on reducing pain, swelling, and the progression of the disease.
Radiology imaging will play an important part in not only diagnosing but also in determining how the disease is progressing. Imaging can be used to look at both the damage being done directly to the joints and bones as well as the soft tissue around the joints and bones.