Psoriatic arthritis is a specific type of arthritis that develops in patients with signs and symptoms of psoriasis. Approximately 23 percent of people psoriasis will go on to develop psoriatic arthritis.. The disease can be difficult to diagnose, particularly in its milder forms.
The cause of psoriatic arthritis is unknown. Doctors suspect that genetic, environmental and/or immune factors may play a role. It is classified in the group of diseases called Seronegative Spondyloarthropathies (grouped with other conditions including Behcet’s disease, reactive arthritis, ankylosing spondylitis, Marie-Strumpell arthritis, rheumatoid spondylitis, psoriatic arthritis, and inflammatory bowel disease.) Approximately 40 percent of people who develop psoriatic arthritis have a family member with either psoriasis or arthritis.
Psoriatic arthritis can start slowly with mild symptoms, or it can develop quickly. When left untreated, psoriatic arthritis can be a progressively disabling disease.
- Stiffness, pain, swelling and tenderness of the joints and the soft tissue around them
- Reduced range of motion
- Morning stiffness and tiredness
- Nail changes, including pitting or lifting of the nail – found in 80 percent of people with psoriatic arthritis
- Redness and pain of the eye, such as conjunctivitis
Joints commonly affected by psoriatic arthritis are the hands, wrists, knees, ankles, lower back and neck. Psoriatic arthritis can develop any time, but most commonly between the ages of 30 and 50, affecting men and women equally.
Five Types of Psoriatic Arthritis (PsA)
Similar to rheumatoid arthritis but generally milder with less development of joint deformities. It usually affects multiple symmetric (same joints on both sides of the body) pairs of joints and can be disabling. The associated psoriasis is often severe. About 50 percent of people with this form of PsA will develop varying degrees of progressive destructive disease of the joints.
Asymmetric (not occurring in the same joints on both sides of the body) arthritis usually involves only one to three joints. It may affect any joint such as the knee, hip, ankle or wrist and even a single finger. The digits of the hands and feet may develop diffusely enlarged “sausage” digits, caused by swelling and inflammation of the joints and tendons. The joints may be warm, tender and red. Individuals may experience periods of joint pain that is usually responsive to treatment. This form is generally more mild, although some will develop disabling disease.
Distal Interphalangeal Predominant (DIP)
This form of arthritis, although considered the “classic” type, occurs in only about 5 percent of people with psoriatic arthritis. It primarily involves the distal joints of the fingers and toes (the joint closest to the nail). Sometimes it is confused with osteoarthritis, but nail changes are usually prominent.
In 5 percent of individuals, inflammation of the spinal column is the predominant symptom. Common symptoms include pain, stiffness and limited motion of the neck, lower back, sacroiliac or spinal vertebrae. Peripheral disease may also be present in the hands, arms, hips, legs and feet. Spondylitis, when severe, may be associated with generalized symptoms.
This is a severe, deforming and destructive arthritis that affects fewer than 5 percent of people with psoriatic arthritis. It principally affects the small joints of the hands and feet, although associated neck or lower back pain is frequent. This type can progress over months and years. Arthritic flares and remissions tend to coincide with skin flares and remissions.
The Approach to Treatment
Goals for therapy in psoriatic arthritis (PsA) include pain relief, reduction in swelling, and joint preservation. Physicians will choose treatments based on the subtype of PsA, its severity and an individual’s response to treatment.
Given the risk for progressive deterioration of the joints and spine early diagnosis and treatment are important to prevent irreversible damage. Early treatment can slow the disease and preserve function and range of motion. Early indicators of severe disease include onset at a young age, spinal involvement and the results of certain blood studies.
Categories of Treatment
Drugs for the treatment of PA can be divided into two categories:
- Nonsteroidal anti-inflammatory drugs (NSAIDs), including over-the-counter medications such as aspirin and ibuprofen as well as prescription formulations. Benefits include decreasing the symptoms of PsA, including inflammation, joint pain and stiffness.
- Disease-modifying antirheumatic drugs (DMARDs), whose purpose is to relieve more severe symptoms and slow or stop joint and tissue damage and progression of PsA.
Corticosteroids may play a therapeutic role in some cases. Heat, warm water soaks, exercise programs and physical therapy are used as adjunctive treatments in PsA. The following treatments are not listed in an ascending order of importance. A physician must evaluate each PsA case individually.
Step 1: Treating the Symptoms
Aspirin & NSAIDs
Though it may help reduce pain and stiffness in PsA, aspirin is often less effective for PsA than for rheumatoid arthritis. It may also cause bleeding in the stomach, ulcers and easy bruising.
Prescription and nonprescription NSAIDs are effective for many people with PsA in controlling swelling, pain and morning stiffness, and in improving range of motion to joints. They can help reduce the limitation to daily activities often caused by arthritis. Many different brands of NSAIDs are available. The specific drug to be used is determined between the patient and their physician. NSAIDs and aspirin generally do not significantly alter psoriasis skin lesions, although certain NSAIDs have been reported to trigger flares of psoriasis. Some NSAIDs, when taken in high doses or over long periods of time, carry a risk of causing stomach problems, including ulcers and gastrointestinal bleeding. Most PsA patients however tolerate NSAIDs quite well with few side effects.
NSAIDs and/or aspirin are sufficient treatment for PsA patients. Acetaminophen (Tylenol) may be added for pain relief. A physician may consider stronger medications when NSAIDs and aspirin fail to control symptoms and progression of the disease is evident.
Step 2: Slowing the Disease
Methotrexate is a drug used widely and successfully for treating PsA and rheumatoid arthritis. Available by pill or injection, it is effective at relieving the symptoms associated with PsA, and it may retard the joint and bony destruction caused by certain forms of PsA.
Methotrexate usually is well tolerated at low doses. A number of side effects do exist including the long-term potential of damaging the liver. With careful management and dosage, the drug can be used safely for years by selected individuals.
Cyclosporine is an oral medication that suppresses the immune system and is primarily used for preventing rejection of transplanted organs. It is approved for treating psoriasis, showing improvement in both skin and joint disease. Use of cyclosporine has increased recently, and may be combined with methotrexate in certain individuals. Frequent blood tests are required due to the risk of kidney damage.
Sulfasalazine, a sulfa drug, has been increasingly used for PsA as well as rheumatoid arthritis. Approximately one-third of PA patients respond rapidly to this therapy (usually within four to eight weeks), which may also induce more sustained remissions of the disease.
This drug has less dangerous side effects than some other systemic psoriasis and psoriatic arthritis treatments, including methotrexate, so a trial of sulfasalazine may be worthwhile for some. However, many people cannot tolerate sulfasalazine because of side effects, including nausea, vomiting and loss of appetite.
An oral medication similar to that of methotrexate and used for the successful treatment of both rheumatoid arthritis and PsA. Routine blood testing is necessary to identify potential medication side effects.
Antimalarial therapy, commonly used with success in rheumatoid arthritis, has been used to treat PsA. Certain antimalarials however may cause skin psoriasis to worsen in certain patients. Some experts believe antimalarials should not be used at all for PsA, however it has been reported that the antimalarial hydroxychloroquine (Plaquenil) is less likely to cause a psoriatic flare than quinacrine or chloroquine, if a person needs to take an antimalarial in order to travel. A health care provider should be consulted about the available antimalarial treatments and alternatives.
Acitretin (brand name Soriatane in the U.S.), a systemic vitamin A derivative (retinoid) approved for severe skin psoriasis, may be effective for some PsA patients. It has not shown to be effective in joint disease. Oral retinoids carry with them the risk of birth defects and the possibility of producing skeletal side effects with long-term use.
The administration of a photosensitizing drug called psoralen with ultraviolet light A (PUVA) may sometimes improve psoriatic plaques affecting the limbs. Generally it is used in combination with other medications. It is not helpful in treating PsA of the spine.
There are ew short-term side effects, but has the long-term potential to increase the risk of certain skin cancers. The amount of risk is based on several factors, including the individual’s skin type, the number of treatments and the total “dose” administered.
Injection of gold salts and administration of gold capsules by mouth have both been reported to be effective in treating arthritis affecting the limbs, but not for treating arthritis of the spine. There is some disagreement about whether it worsens or improvement psoriatic skin lesions. Routine blood and urine samples are required to prevent kidney damage.
Use of gold has declined somewhat in recent years as new therapies have been developed.
Azathioprine (brand name Imuran) suppresses the immune system and is approved for use in certain types of arthritis. It has potent anti-inflammatory effects. Blood tests must be performed frequently as the drug can cause life-threatening effects on the bone marrow. Azathioprine increases the risk of malignancies in later years.
Steroid medications taken orally (by mouth) are not generally recommended for long-term treatment of PsA, although in some circumstances they may be needed for relief of acute, severe joint inflammation and swelling. Generally, large doses of steroids injected into muscles should be avoided as the psoriatic skin lesions may worsen with the discontinuation of steroid treatment.
Occasionally, severe forms of psoriasis, such as pustular psoriasis, may be provoked by the use of systemic steroids. However low-dose steroid injections to inflamed joints, tendons and the area around joints can improve range of motion and limit contraction.
Biologic Therapies/Newer Therapies
Tumor Necrosis Factor Alpha Inhibitors (TNF-alpha inhibitors)
There are five formulations within this family of medications, they include Infliximab (Remicade), Etanercept (Enbrel), Adalimumab (Humira), Certolizumab (Cimzia) and Golimumab (Simponi). They have been approved by the U.S. Food and Drug Administration for treating various autoimmune and inflammatory conditions including rheumatoid arthritis, inflammatory bowel disease and psoriatic arthritis as well. They may be given as both injections (at home or in the office) or as infusions (office-based). These therapies, called “biologic response modifiers,” target the immune system response that leads to inflammation. There are very few side effects, although there can be an increased risk of infections.
Ustekinumab (Brand Name Stelara)
Another form of biologic therapy which blocks the function another set of inflammatory targets. It is given as an injection in the doctor’s office every 12 weeks. It has shown good efficacy in both psoriatic skin lesions and arthritis.
Secukinumab (Brand Name Cosentyx)
Recently approved for the treatment of plaque psoriasis and initial studies for psoriatic arthritis have been promising. Given as an injection and targets another inflammatory target of the immune system
Apremilast (Brand Name Otezla)
Another newer therapy for the treatment of plaque psoriasis and psoriatic arthritis. It is given as a pill twice daily and is an alternative for those patients who do not want to receive injectable or infusible medications.
- Diet and Climate – Dietary modification has not been found to be useful for PsA. A warm, stable climate may have some influence on the disease symptoms.
- Surgery – Can help individuals with joint destruction that limits motion and function despite medical therapy. (Skin affected by psoriasis does not appear to cause any special problems with infection during surgery.)
- Rehabilitation – Physical therapy and rehabilitation are used to maximize the function of an arthritic joint.
- Exercise – Exercise is essential to preserve strength and maintain range of motion. Isometric exercise is often prescribed because it appears to be less damaging to inflamed joints. A range of motion program should be coupled with a stretching program.
- Pain lasting for two hours after exercise is a sign of overdoing it or of choosing the wrong exercise. Stretching exercises are part of the treatment and are especially useful for spinal arthritis.
- Splints – In addition to exercise and local pain therapy, a splint may be used to support a joint in a position to improve function and relieve pain and swelling.
- Other –
- Heat, cold and rest are used to relieve pain. Immobilizing an inflamed swollen area while using cold packs can reduce the swelling and improve range of motion.