It is a form of arthritis that tends to affect people with the autoimmune condition psoriasis, but it can also affect people without psoriasis. People who have a family member with psoriasis may also develop psoriatic arthritis (PsA).
The most common symptoms of PsA are:
Swollen and painful joints
PsA can affect any joint in the body. The most common areas are the hands, feet, knees, ankles, and spine. The neck and wrists can also be affected.
If it occurs in the fingers, PsA will generally affect the joint closest to the nail.
Severity can vary from patient to patient, with some mild cases affecting one or two joints, while more severe cases can affect a number of joints across the body.
If four or fewer joints are affected, PsA is considered mild and is known as oligoarticular. If four or more joints are affected, it is severe and is called polyarticular.
Stiffness and reduced movement
As well as swelling, one of the key symptoms of PsA is stiffness in the joints, particularly in the morning or after rest.
Stiffness can occur with or without pain and in any joint.
It is quite difficult to define stiffness, but people have described it as an aching sensation and a problem moving.
If this continues for longer than an hour, it could be a sign of PsA.
As with other types of inflammatory arthritis, fatigue can be a problem. Those with PsA have described it as "wipeout." Around 29 percent say they have severe fatigue, while 50 percent have moderate to severe fatigue.
Although fatigue can occur in people with PsA, it does not develop as a direct result of it. For example, people with PsA often develop depression and anxiety and it is these conditions that can cause fatigue.
Abnormalities in the finger and toenails are something to watch out for. Pits, or small depressions, can appear while the nails can become detached from the bed.
There can also be infection that mimics that of a fungal infection.
Swollen fingers and toes
One of the symptoms of PsA that sets it apart from other forms of arthritis is swollen, "sausage-like" fingers and toes.
The joints in fingers nearest to the nail can also be affected.
Generally, if a person has a current case of psoriasis and changes in their nails, a doctor will likely suspect PsA. The doctor will be able to determine whether the person does have PsA through a physical examination, blood tests, MRI scans, or X-rays.
PsA will mostly occur in people aged between 40-and 50-years-old, however, anyone can be affected, including children and the elderly.
This is according to a study conducted by the National Center of Biotechnology. The researchers also found that PsA affects around 0.16 percent of people in the United States, or 7.2 in every 1 million of the population. PsA has been found to be more common in the U.S. and Europe than Asia.
Around 30 percent of people with psoriasis will also have PsA. In around 85 percent of cases, psoriasis will occur before PsA. As a result, anyone who has psoriasis and who starts to experience aches and pains in their joints should tell their doctor.
Causes and risk factors
It is not known exactly what causes PsA. However, some key factors associated with it include:
Stress is sometimes associated with PsA and those with psoriasis should aim to reduce stress and relax when possible.
- Stress: People should with psoriasis should try and reduce stress, and relax as much as possible.
- Infection: PsA and psoriasis are not infectious, but can be caused by strep throat.
- Skin injuries: Trauma to the skin of a person with psoriasis can be a trigger for PsA. This is known as Koebner's phenomenon after the doctor who discovered it.
- Medication: Certain medications can act as a trigger. These include lithium, antimalarials, inderal, quinidine, and indomethacin.
- Heredity: Around 40 percent of those with PsA have family members who also have psoriasis or arthritis.
Foods to avoid
Despite a lack of scientific evidence, some people find that changing their diet can help.
- Losing weight, if appropriate, as the risk of developing PsA increases with BMI
- Choose heart-healthy foods, such as fish, lean meat, and low-fat products
- Avoid foods that may encourage inflammation, such as fatty red meats, processed foods, dairy produce, and items with a high sugar content
- Getting checked for celiac disease, as the incidence seems to be higher in people with PsA. If the result is positive, you may consider going gluten-free.
- Consuming more omega-3 fatty acids and vitamin D, possibly through supplements.
The benefits of these dietary changes are not confirmed, but they may help. Speak to your doctor before making any changes.
Cases of PsA can lead to joint damage, deformity, and reduced mobility. Early diagnosis is vital, as these can occur even in the early stages of the condition.
There is a direct link between how long PsA is present before it is diagnosed and treated and increased risk factors. Doctors are also trying to reduce the time between diagnosis of psoriasis and subsequent diagnosis of PsA.
When to see a doctor
As problems connected to PsA can increase the longer it goes untreated, people with any concerns should see a doctor straight away.
Because PsA is a long-term disease, the relationship between an individual and their doctor is very important to ensure that it is treated correctly. If PsA is diagnosed, people should try to see a rheumatologist as soon as they can.
Most cases of PsA are considered mild and only occur in a few joints. However, there is often a direct connection between how serious PsA is when it is first diagnosed and treated and the long-term effects.
The most serious potential problems with PsA include:
- damaged joints
- deformity in the hands, feet, and spine
- decreased movement
- reduced health-related quality of life
The outlook can also depend on whether the PsA is considered mild or severe. In general, those who have PsA can lead normal lives with the right treatment.