If the small joints between the vertebrae (spine bones) are inflamed, it might cause back pain.
Psoriatic arthritis can affect many different joints and vary in its severity. It often affects the hands, feet, elbows, knees, neck or vertebrae. More than five joints typically become inflamed, including the joints at the end of the fingers and toes. These joints are especially prone to becoming deformed in severe cases.
Most people who have psoriatic arthritis also have nail psoriasis. This can lead to small dents in the nails, which may become thicker, change color or start peeling off too. Nail psoriasis is difficult to treat and sometimes mistaken for a fungal nail infection.
Causes and risk factors
Psoriatic arthritis is an autoimmune disease: The immune system is too active and releases more inflammation-causing chemical messengers (cytokines).
Genes play a major role here. Your risk of developing psoriatic arthritis is much higher if one of your parents or a brother or sister has had psoriasis or psoriatic arthritis.
About 25% of people who have psoriasis will develop psoriatic arthritis at some point. It usually starts between the ages of 30 and 50 years, but it can occur at any age.
In about 80-90% of people who have psoriatic arthritis, it is caused by psoriasis. The psoriatic arthritis often only develops after many years. But the joints may become inflamed before skin symptoms become visible, or without any skin symptoms at all.
There is no clear link between the severity of psoriasis and the severity of psoriatic arthritis. Some people have severe psoriasis on their skin, but no problems with their joints. Others have psoriatic arthritis, but no symptoms on their skin, or hardly any.
It's very difficult to predict how psoriatic arthritis will continue to develop. Some people have inflammation in just a few joints, while in others it affects more joints over time.
If the inflammations are severe and the psoriasis progresses, the joints might become permanently damaged and deformed. Treatment with disease-modifying medications can stop or delay joint damage, though.
Doctors use the following approaches and information to diagnose psoriatic arthritis and to rule out other types of joint inflammation:
Physical examination: Certain changes are typical of psoriatic arthritis. For instance, the inflammation may affect a whole finger (dactylitis) or the tendons and tendon sheaths of the hands or feet (enthesitis), such as the Achilles tendon.
Family medical history: If psoriasis is known to run in someone's family, any joint pain they have is more likely to be caused by psoriatic arthritis.
Blood tests: 90% of people with psoriatic arthritis don't have any of the antibodies in their blood that are typical of rheumatoid arthritis. So if none of these "rheumatoid factors" are found, it's more likely to be psoriatic arthritis.
Imaging techniques: X-rays and ultrasound scans can help to find out whether someone has psoriatic arthritis, rheumatoid arthritis or osteoarthritis. The images can also be used to get a better idea of how extensive the joint damage is and what type of damage is involved. But changes in the joints are often not yet clearly visible in the early stages of psoriatic arthritis.
Measuring uric acid levels: High levels of uric acid in the blood are a sign that the joint problems are being caused by gout rather than psoriatic arthritis.
An estimated 10% of all people who have psoriatic arthritis don't have any visible skin changes. That makes it more difficult for doctors to tell whether it is psoriatic arthritis or another type of joint disease.
Treatments for psoriatic arthritis have various goals, including the following:
relieving the symptoms such as pain and swelling,
keeping the joints working properly, and
preventing long-term damage to the joints.
If you have psoriatic arthritis, there are a few things you can do on your own to reduce the inflammation, strengthen your joints and prevent exhaustion. They include getting enough exercise, not smoking and losing weight if you are very overweight. The effectiveness of these measures has hardly been tested at all in studies, though.
Medication plays a large role in the treatment of psoriatic arthritis. In mild cases that only affect the knees, elbows or wrists, treatment with NSAID painkillers is sometimes enough. These types of painkillers include diclofenac, ibuprofen and naproxen, for instance. They can be taken as tablets or applied to the inflamed joints as a gel or cream.
If this isn't effective enough or if there is good reason to believe that the disease will get worse, treatment with disease-modifying drugs is recommended. These drugs reduce the inflammation in the joints. This allows them to both relieve the symptoms and prevent or delay damage to the joints. Examples of disease-modifying drugs include methotrexate, leflunomide and medications called biologics.
The often unpredictable symptoms of psoriatic arthritis can make it hard for many people to make plans in everyday life. Always waiting for the next flare-up can also be very difficult emotionally.
Some people who have psoriatic arthritis worry about not being to keep up with things they have to do or being a burden to others. Most activities can be a challenge if you feel exhausted.
But despite all the difficulties, there are also phases when the symptoms get better for a while. Over time, many people develop a good feel for their body and learn to interpret their body's signals and react to them.
It's often helpful to learn all about psoriatic arthritis and the treatment options, develop practical strategies to cope with the disease, and not to fight it. Keeping your expectations realistic and accepting the disease as part of your life can make it easier to live with it.
When people are ill or need medical advice, they usually go to see their family doctor first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.
There are many sources of support for people with psoriasis, These include support groups and information centers. Support services are often organized quite differently from region to region, though. Our list of places to contact may help you to find and make use of the help you need.
IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.
Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.
Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.
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