Psoriatic Arthritis Symptoms and Diagnosis

Having psoriasis increases the chance that you may later develop psoriatic arthritis, though most people with psoriasis do not develop psoriatic arthritis. Up to a third of people with psoriasis have psoriatic arthritis, compared to less than 1% of adults in the general Canadian population.

People who develop psoriatic arthritis can have genes that predispose, or give them more potential, to have the disease, but those genes are not always triggered to develop psoriasis or psoriatic arthritis. Researchers are still working to understand how genetics play a role in who develops psoriatic arthritis.

Psoriatic arthritis affects males and females in equal numbers. Its prevalence in people who are intersex or differences across multiple genders is unknown.

Some hormonal changes may be linked to psoriatic arthritis or psoriasis flares. Hormone changes during and after pregnancy, during breast or chest feeding, throughout the menstrual cycle, and even oral contraception use may relieve or trigger psoriatic arthritis symptoms depending on each person’s experience with the disease.

There is currently no clear indication that hormone replacement therapy (HRT) has an impact on symptoms or likelihood of developing psoriatic arthritis, though more research is needed in this area.

Psoriatic arthritis can affect people of any age, but it is more commonly diagnosed in people between the ages of 30-50 years.

Psoriatic arthritis is not contagious, though symptoms of psoriatic arthritis may appear for the first time after having an infection. Other environmental factors such as stress or physical injury could also lead to the onset of symptoms.

Cigarette smoking can increase the risk of developing psoriatic arthritis among the general population. Smoking is the strongest environmental risk for the development of psoriatic arthritis and for having a more severe form of joint pain and stiffness.

Many people who develop psoriatic arthritis already have symptoms or a diagnosis of psoriasis. If any new or unexplained joint pain develops, this may be an early sign of psoriatic arthritis. Sometimes arthritis occurs before the skin rash from psoriasis is visible. If any of the following symptoms last for more than two weeks, you should see your doctor: 

• You start to feel unusual pain and stiffness in a joint(s), which may include new back pain and stiffness.
• The pain and stiffness is worse in the morning, typically lasting an hour or more than before the joints loosen up and start feeling better.
• The pain and stiffness can be with you (to some degree) most of the day, even causing discomfort while you try to sleep at night.
• You feel more tired than usual, without any other cause.

The place where a tendon or ligament attaches to bone is called an enthesis (plural: entheses). There are over 100 entheses in your body with many ligaments and tendons attaching to bones. When these areas become swollen or inflamed, it is called enthesitis. People with psoriatic arthritis may also experience pain in the tendons or ligaments due to inflammation caused by enthesitis. This can be experienced in addition to painful joints.

Some of the more common spots for enthesitis are on the back of the heels, underneath the heel, on the sides of the elbows, and on the outside of the hips.

Psoriasis can cause changes in nails, such as pitting, or separation from the nail bed. People with nail psoriasis are more likely to develop psoriatic arthritis.

Nail psoriasis may be a form of enthesitis. The presence of nail psoriasis may indicate the presence of enthesitis, which may progress to psoriatic arthritis.

In some people, swelling of the entire toe or finger can occur. This is called dactylitis or ‘sausage’ digit(s).

Psoriasis: The most common form of psoriasis is called plaque psoriasis, and can cause skin to have raised, inflamed, scaly patches of skin that may be painful or itchy. In people with darker or more pigmented skin (i.e., black, brown) plaques may be thicker, darker, and have a purplish, grey or brown colour. For people with lighter pigmented skin (i.e., white), the plaques may appear red, or have a silvery white scale of built-up dead skin cells.

Uveitis is an inflammatory condition that affects the uvea (middle layer) of the eye. It can cause pain, redness, and inflammation in one or both eyes. It can also cause blurred or distorted vision and may cause permanent damage or vision loss if not treated.

Uveitis affects about 7% of people with psoriatic arthritis. It is important to monitor your symptoms and let your doctor or healthcare team know if you experience pain in or behind your eyes, have blurry vision, become light sensitive, or have other vision changes with no other known cause. Catching symptoms early is important to minimizing changes to your vision.

A regular check up from an eye doctor (optometrist or ophthalmologist) may help catch early symptoms of eye inflammation and is an important part of maintaining eye health.

There are five general patterns of psoriatic arthritis:  

• Asymmetric psoriatic arthritis affects one to four joints on different sides of the body. 
• Symmetric psoriatic arthritis involves many more joints and looks very much like rheumatoid arthritis (RA).
• Distal psoriatic arthritis involves the end joints of the fingers closest to the nails.  
• Spinal psoriatic arthritis involves the joints of the spine and the sacroiliac joints that link the spine to the pelvis.  
• Destructive psoriatic arthritis is an uncommon but severe, painful, deforming type of arthritis, also known as arthritis mutilans.  

The pattern of your psoriatic arthritis may change over time.