Individuals who have a family member with psoriasis may also develop psoriatic arthritis (PsA).
- Psoriatic arthritis (PsA) can cause swollen extremities, nail changes, stiffness, joint inflammation, and fatigue.
- The condition most commonly affects people between the ages of 40 and 50 years.
- The prevalence of the condition in the United States is 0.16 percent.
- PsA can be brought on by stress, skin injuries, genetics, and infections.
The most common symptoms of PsA are:
Swollen and painful joints
Fatigue is a common symptom of psoriatic arthritis.
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 person to person, with symptoms in some people affecting one or two joints and more severe presentations affecting a number of joints across the body.
If four or fewer joints are affected, PsA is considered to be mild and is known as oligoarticular PsA. 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 of 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 that causes difficulties with movement.
Stiffness that continues for longer than an hour could be a sign of PsA.
As with other types of inflammatory arthritis, fatigue can be a symptom. Those with PsA have described it as "wipeout." Around 29 percent say they have severe fatigue, while 50 percent have moderate to severe fatigue.
The inflammation from PsA causes the release of proteins called cytokines, and these can lead to fatigue. Other conditions common in people with PsA can also cause fatigue, such as anemia, obesity, diabetes, sleep problems, depression, and anxiety.
Watch out for abnormalities in the finger and toenails. Pits, or small depressions, can appear, and the nails can become detached from the bed.
An infection that mimics a fungal infection can also occur.
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.
Symptoms can be similar to three other arthritic diseases: Rheumatoid arthritis, gout, and reactive arthritis.
Generally, if a person has a current case of psoriasis and changes in their nails, a doctor will try to rule out PsA. The physician will be able to determine whether the person has PsA through a physical examination, blood tests, MRI scans, or X-rays.
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Image credit: Doc James, 2010, own work
Stiffness in the hands and wrists
PsA is most common between the ages of 40 and 50 years. However, anyone can be affected, including children and older adults, 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 is 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 people, psoriasis will occur before PsA. As a result, anyone who has psoriasis and 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 are linked to its development, including:
- Stress: People with psoriasis should try and reduce stress using relaxation techniques.
- Infection: PsA and psoriasis are not infectious but can be caused by strep throat.
- Skin injuries: Skin trauma that occurs in a person with psoriasis can be a trigger for PsA. This is known as Koebner's phenomenon.
- Medication: Certain medications can act as a trigger. These include lithium, Inderal, quinidine, indomethacin, and antimalarial medications.
- Heredity: Around 40 percent of those with PsA have family members who also have psoriasis or arthritis.
Foods to avoid
Heart-healthy foods, such as fish, are thought to prevent aggravation of psoriatic arthritis, although more research is needed.
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 products, 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.
PsA can lead to joint damage, deformity, and reduced mobility. Early diagnosis is vital, as these complications can occur even in the early stages of the condition.
There is a direct link between the length of time PsA is present in the body before treatment and the risk of complications. 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.
PsA is a long-term disease, so to ensure that they treated correctly, the relationship between an individual and their doctor is important. 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. Early diagnosis and treatment can help prevent long-term complications.
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 after receiving the right treatment.