What is psoriatic arthritis?
Psoriatic arthritis is a form of inflammatory arthritis characterized by joint pain, swelling, and morning stiffness. It is associated with having psoriasis or a family history of psoriasis. Both psoriasis and psoriatic arthritis are chronic autoimmune diseases – meaning, conditions in which certain cells of the body attack other cells and tissues of the body.
Psoriatic arthritis can vary from mild to severe, it can present in the following ways:
- Oligoarticular, affects four or fewer joints in the body.
- Polyarticular, affecting four or more joints.
- Spondylitis, less common and affecting the spine, hips, and shoulders.
Who is at risk for psoriatic arthritis?
Psoriasis affects 2-3 percent of the population or approximately 7 million people in the U.S. and up to 30% of these people can develop psoriatic arthritis. Psoriatic arthritis occurs most commonly in adults between the ages of 35 and 55; however, it can develop at any age. Psoriatic arthritis affects men and women equally.
It is possible to develop psoriatic arthritis with only a family history of psoriasis and while less common, psoriatic arthritis can occur before psoriasis appears. Children of parents with psoriasis are three times more likely to have psoriasis and are at greater risk for developing psoriatic arthritis. The most typical age of juvenile onset is 9-11 years of age.
Symptoms and Causes
What are the symptoms of psoriatic arthritis?
The symptoms of psoriatic arthritis may be gradual and subtle in some patients; in others, they may be sudden and dramatic. It may be mild, affecting only one joint or can be severe, affecting multiple joints. Not all patients experience all symptoms.
The most common symptoms of psoriatic arthritis are:
- Pain or aching, tenderness, and/or swelling in one or more joints - most commonly hands, feet, wrists, ankles, knees.
- Joint stiffness most notable in the morning or with prolonged inactivity such as sitting for a long time.
- Reduced range of motion in affected joints.
- Pain or stiffness in the lower back.
- Tenderness, pain, or swelling where tendons and ligaments attach to the bone (enthesitis), such as the Achilles’ tendon of the heel.
- Swelling of an entire finger or toe with a sausage-like appearance (dactylitis).
- Silver or gray scaly spots on the scalp, elbows, knees, and/or the lower spine.
- Small, round spots called papules that are raised and sometimes scaly on the arms, legs and torso.
- Pitting (small depressions) of the nails.
- Detachment or lifting of fingernails or toenails.
- Inflammation of the eye (iritis or uveitis).
What causes psoriatic arthritis?
The cause of psoriatic arthritis is unknown. Researchers suspect that it develops from a combination of genetic (heredity) and environmental factors. They also think that immune system problems, infection, obesity, and physical trauma play a role in determining who will develop the disease. Psoriasis itself is neither infectious nor contagious.
Recent research has shown that people with psoriatic arthritis have an increased level of tumor necrosis factor (TNF) in their joints and affected skin areas. These increased levels can overwhelm the immune system, making it unable to control the inflammation associated with psoriatic arthritis.
Diagnosis and Tests
How is psoriatic arthritis diagnosed?
There is no single test to diagnose psoriatic arthritis. Healthcare providers (MD, DO, NP, PA) make the diagnosis based on a patient's medical history, physical exam, blood tests, and X-rays of the affected joints. Magnetic resonance imaging (MRI) is generally not needed except in unusual circumstances.
Laboratory tests that may be helpful in diagnosis or used to monitor disease activity include:
- Rheumatoid factor and anti-CCP - types of blood tests to help diagnose rheumatoid arthritis.
- HLA-B27 - blood test to help diagnose, may also be indicated with a family history of psoriasis or psoriatic arthritis.
- Sedimentation rate (ESR) and C-reactive protein (CRP) - may indicate inflammation.
X-rays are not usually helpful in making a diagnosis in the early stages of the disease. In the later stages, X-rays may show changes that are more commonly seen only in psoriatic arthritis. One such finding is called the "pencil-in-cup," which describes the finding where the end of the bone gets whittled down to a sharp point. This finding indicates more severe inflammatory changes to joints, which may require more aggressive treatment.
The diagnosis of psoriatic arthritis is easier for your healthcare provider to confirm if psoriasis exists along with symptoms of arthritis. However, in as many as 15% of patients, symptoms of psoriatic arthritis appear before symptoms of psoriasis. Since the disease symptoms can vary from patient to patient, it is even more important to meet with your healthcare provider when symptoms worsen or new symptoms appear.
Management and Treatment
What are the treatment options for psoriatic arthritis?
The aim of treatment for psoriatic arthritis is to control the disease and relieve symptoms. Treatment may include any combination of the following:
- Medication options, including nonsteroidal anti-inflammatory drugs (NSAIDs); corticosteroids (intermittent use); disease modifying anti-rheumatic drugs (DMARDs); and biologics.
- Heat and cold therapy.
- Joint protection and energy conservation.
Choice of medications depends on disease severity, number of joints involved, and associated skin symptoms. During the early stages of the disease, mild inflammation may respond to nonsteroidal anti-inflammatory drugs (NSAIDs). Cortisone injections may be used to treat ongoing inflammation in a single joint. Oral steroids, if used to treat a psoriatic arthritis flare, can temporarily worsen psoriasis. Long-term use of oral steroids should be avoided when possible due to the negative effects on the body over time.
DMARDs are used when NSAIDs fail to work and for patients with persistent and/or erosive disease. DMARDs that are effective in treating psoriatic arthritis include: methotrexate, sulfasalazine, and cyclosporine.
Biologic agents are an important consideration when disease control is not being achieved with NSAIDS or DMARDs. Biologics have been utilized for the treatment of psoriatic arthritis since 2005 and are highly effective at slowing and preventing progression of joint damage. Your healthcare provider will complete additional laboratory tests and review safety considerations before initiating a medication regimen. Gaining good control of psoriatic arthritis and psoriasis is important to avoid increased systemic risks, particularly heart disease.
There are also many non-pharmacologic therapies that can be used in addition to medication to help with your joint symptoms. Some of these therapies include:
Moderate, regular exercise may help relieve joint stiffness and pain caused by psoriatic arthritis. Range-of-motion and strengthening exercises as instructed and under the direction of a physical or occupational therapist may be helpful in combination with low-impact aerobics. Before beginning any new exercise program, discuss exercise options with your healthcare provider. Regardless of the exercise program you select, choose one you enjoy so that you continue to do it. Be mindful that too rigorous or improper exercise programs may make psoriatic arthritis worse.
Heat and cold therapy
Intermittent heat and cold therapy involves choosing or switching the use of moist heat and cold therapy on affected joints. Moist heat – supplied by a warm towel, hot pack, or warm bath or shower – helps relax aching muscles and relieve joint pain, swelling, and soreness. Cold therapy – supplied by a bag of ice or even a bag of frozen vegetables wrapped in a towel – can reduce swelling and relieve pain by numbing the affected joints.
Joint protection and energy conservation
Daily activities should be performed in ways that reduce excess stress and fatigue on joints. Proper body mechanics (the way you position your body during a physical task) may not only protect joints, but also conserve energy. People with psoriatic arthritis are encouraged to frequently change body position at work, at home, and during leisure activities. Maintaining good posture – sitting/standing up straight and not arching your back – is helpful for preserving function.
Your healthcare provider may recommend splinting your joints to ease inflammation or problems with joint alignment or stability. However, to maintain movement in these joints, the splints should be removed from time to time and gentle range-of-motion exercises should be performed.
Most people with psoriatic arthritis will never need surgery. However, severely damaged joints may require joint replacement surgery. The goal of surgery is to restore function, relieve pain, improve movement, or improve the physical appearance of the affected area.
What treatment is right for me?
The type of treatment will depend on how severe your symptoms are at the time of diagnosis with the goal being to control the disease to the point of remission and avoid complications. Medications may need to be changed over time to continue to maintain control and avoid disease progression and systemic effects. Some early indicators of more severe disease include onset at a young age, multiple joint involvement, and spinal involvement. Good control of the skin is important in the management of psoriatic arthritis. In many cases, you may be seen by two different types of healthcare providers, one in rheumatology and one in dermatology.
Early diagnosis and treatment can relieve pain and inflammation and help prevent progressive joint involvement and damage. Without treatment psoriatic arthritis can potentially be disabling, cause chronic pain, affect quality of life, and increase risk of heart disease. It is important to update your healthcare provider when you have a change in symptoms or if your medication regimen is no longer effective.
Living with psoriatic arthritis
There is no cure for psoriatic arthritis. However, by understanding the disease and knowing what to expect, you can learn different ways to complete daily tasks or plan activities at times of the day when you are least bothered by its effects. Once you understand and learn to predict the ways in which your body responds to the disease, you can use exercise and therapy to help decrease discomfort, stress and fatigue.
There is a significant list of comorbidities related to PsA. These include these 11 conditions:
- Cardiovascular disease (CVD), diabetes, obesity and metabolic syndrome — This list represents the most common conditions associated with PsA. “Diabetes, obesity and metabolic syndrome are all tied into the cardiovascular risk, because PsA can have a heavy inflammatory burden on the body,” Dr. Husni says.
- Inflammatory bowel diseases (IBD) – These illnesses, such as Crohn’s disease and ulcerative colitis, do have an elevated incidence in patients with PsA. Researchers are still studying the link.
- Autoimmune ophthalmic disease – Eye disease is commonly associated with PsA. Up to 25 percent of patients can get uveitis, an inflammatory condition, according to Dr. Husni. Your rheumatologist will work closely with an ophthalmologist if eye disease is present.
- Osteoporosis, fatty liver disease, chronic kidney disease, anxiety and depression — This list represents the least common conditions associated with PsA. A new medication to treat PsA called apremilast (Otezla®) it can also cause an increase in depression, Dr. Husni cautions. So it may not be the optimal choice for patients who already have anxiety or depression.