What Is Psoriatic Arthritis?
Picture of severe psoriatic arthritis involving the finger joints
Psoriatic arthritis is a joint disease characterized by both psoriasis and a related form of inflammatory arthritis. Psoriasis is a common skin condition. A person with psoriasis typically has patches of raised, red, scaly skin. The affected skin can look different depending on the type of psoriasis the individual has. Arthritis is joint inflammation. Psoriatic arthritis is a particular type of aggressive and potentially destructive, inflammatory arthritis.
Psoriatic arthritis is an autoimmune disease, meaning that the immune system attacks one's own tissues. Rarely, a person can have psoriatic arthritis without having obvious psoriasis. Usually, the more severe the skin symptoms are, the greater the likelihood a person will have psoriatic arthritis.
Psoriasis affects a small percentage of white people in North America, and is less common in African-American and Native-American people. Psoriatic arthritis affects approximately 15% of people with psoriasis. Many people who have psoriasis may not know that they have psoriatic arthritis.
Males and females are equally likely to have psoriasis. Of patients with psoriatic arthritis, males are more likely to have the form in which the spine is affected (spondylitic form), and females are more likely to have the form in which many joints on both sides of the body are involved (rheumatoid form).
Psoriatic arthritis usually develops in people 35-55 years of age. However, it can develop in people of almost any age.
What Are Psoriatic Arthritis Causes and Risk Factors?
The cause of psoriatic arthritis is not known. It may result from a combination of genetic (family), environmental, and immune factors. A significant percentage of people with psoriasis or psoriatic arthritis have a close relative with the condition. This inherited tendency may be the strongest underlying risk factor. Sometimes psoriasis may be linked to previous infections.
What Are Symptoms and Signs of Psoriatic Arthritis?
People with psoriatic arthritis might not have obvious skin findings, or they might have minimal scaly red skin on the scalp, in the bellybutton, or between the buttocks. Some people with psoriatic arthritis might just have nail abnormalities and arthritis and no other skin symptoms. In one study, arthritis was noted more frequently in people with severe skin involvement. In another study, pustular psoriasis was associated with more severe psoriatic arthritis.
People with psoriatic arthritis may have various nail changes (nail psoriasis). The nails may loosen (onycholysis) and there may be lines going across the nails (side to side rather than root to tip) or yellow spots in the nails. There may also be little pits in the nails. The more pits in the nails, the more likely psoriasis will be present. Usually, if skin and arthritis symptoms begin at the same time, nail findings begin too. Often, if one has symptoms in the joints at the ends of the fingers or toes, then those nails will be affected. Many people with psoriatic arthritis have nail abnormalities. Some people with uncomplicated psoriasis have nail changes. Nail abnormalities are usually present in people who have severe arthritis with deformity in the hands and feet. The nails can also become infected with fungus. The health care provider will assess them and prescribe antifungal medications if so.
Usually, psoriasis occurs before arthritis, sometimes as much as 20 years before arthritis. Tell your doctor if you have a family history of psoriasis because this can be an important clue as to the type of arthritis.
Some people with psoriatic arthritis have eye symptoms, including eye inflammation (conjunctivitis), and inflammation of the iris (iritis), the colored part of the eye. Children with juvenile psoriatic arthritis (see below) are examined annually by an eye doctor to check for eye problems.
Pain and inflammation may develop where your muscles and tendons connect to the bones, especially in the heel and the sole of the foot.
Initial symptoms of psoriatic arthritis may be severe. If symptoms are only in the foot or toe, they may be mistaken for those of gout. (People with psoriasis can have gout. Looking at the joint fluid for gout crystals usually can make the diagnosis clear.) Other people with psoriatic arthritis may only have stiffness and pain and few physically obvious problems. People with HIV often have more severe skin symptoms.
What Are the Types of Psoriatic Arthritis?
If you have psoriatic arthritis, your condition probably falls into one of the patterns below.
Asymmetrical oligoarticular arthritis (arthritis that involves a few joints but not necessarily the same joints on both sides of the body or other similar joints on the same side of the body):
- Usually, the fingers and toes are affected first. The fingers may have a "sausage" appearance (called dactylitis). This occurs in 35% of people with psoriatic arthritis.
- Usually, fewer than five joints are affected at any particular time.
Symmetrical polyarthritis (arthritis that involves similar joints on both sides of the body, much like rheumatoid arthritis) is one of the most common types:
- The hands, wrists, ankles, and feet may be involved.
Distal interphalangeal arthropathy (arthritis in the joints at the ends of the fingers and toes):
- Involvement of the joints at the ends of the fingers and toes occurs in only 5%-10% of people with psoriatic arthritis, most commonly men. (Involvement of the joints at the ends of the fingers and in the big toe can occur in osteoarthritis, but osteoarthritis is much less inflammatory than psoriatic arthritis.) The nail may be involved. The skin around the edges of your nail may be inflamed (called paronychia).
Arthritis mutilans (a long-term form of destructive psoriatic arthritis in which the joints are severely damaged and deformities can be seen, especially in the hands and feet):
- This may occur in people with psoriatic arthritis and can be severe.
- The bone may soften and become absorbed by surrounding tissues (called osteolysis), and the joint may dissolve.
- If the fingers and wrists become shortened with skin folds around them, the condition is called "opera glass hand." This occurs more often in men than in women.
Spondylitis (inflammation of the vertebrae in the spine) with or without sacroiliitis (inflammation of the sacroiliac joint in the pelvis) and inflammation of the hip:
- Spondylitis occurs in a low percentage of people with psoriatic arthritis, usually men.
- People who have other psoriatic arthritis patterns may also have this condition.
- The typical symptom is stiffness of the lower back in the morning, but not everyone has this. It can occur without involvement of the pelvis/hip joints, which often occurs on only one side of the body. Sometimes a person's symptoms do not seem to match the findings on X-rays.
- The vertebrae are not affected evenly. A joint in the neck may be affected and not a lower spine joint.
- Your doctor may notice unusual features on X-rays, such as bony growths on ligaments.
Juvenile psoriatic arthritis (psoriatic arthritis that affects children):
- Juvenile psoriatic arthritis accounts some cases of arthritis in children.
- This often occurs in 9- to 10-year-old girls. It is usually mild, but occasionally it is severe and lasts into adulthood.
- In half of affected children, only one joint is affected. The joints at the ends of the fingers or toes are involved in about half of affected people as well.
- The tendons are inflamed in a significant percentage of affected children. Nails are involved in a majority of affected children, and little pits can often be seen on the nails.
- Bone-growth problems and shortening due to inflammation may occur in almost half of affected children.
- Sacroiliitis (inflammation of the sacroiliac joint in the pelvis) or arthritis of the hip occurs in some affected children.
- Onset of psoriasis and arthritis at the same time occurs more often in children than adults. Arthritis occurs before psoriasis in half of affected children.
When Should Someone Seek Medical Care for Psoriatic Arthritis?
See your doctor if you have joint pain or tenderness. Your health care provider should be consulted for skin or nail problems as well.
What Specialties of Doctors Diagnose and Treat Psoriatic Arthritis?
Health care professionals who treat patients with psoriatic arthritis include primary care providers, rheumatologists, dermatologists, radiologists, orthopedic surgeons, and physical therapists.
What Tests Diagnose Psoriatic Arthritis?
No specific tests are available to determine if you have psoriatic arthritis. Your health care provider will base the diagnosis on X-ray findings and on your signs and symptoms. Your doctor may perform blood tests to assess your arthritis.
Radiographic features on plain film X-rays, CT scan, and MRI scan can be used to distinguish psoriatic arthritis from other types of arthritis.
What Are Psoriatic Arthritis Home Remedies?
If your doctor prescribes a non-steroidal anti-inflammatory drug (NSAID), such as ibuprofen (Motrin, Nuprin, Advil, Excedrin IB), and you have morning stiffness, the best time to take the drug may be in the evening after dinner and again when you wake up. Taking these medications with food will reduce stomach upset. Do not take them within an hour of bedtime because they can injure the lining of the esophagus and stomach.
Exercise is important to keep the pain and swelling of arthritis to a minimum. A good exercise program can improve movement, strengthen muscles to stabilize joints, improve sleep, strengthen the heart, increase stamina, reduce weight, and improve physical appearance.
Usually, a normal amount of rest and sleep will help to reduce joint inflammation and fatigue. In a few people, psoriatic arthritis can cause extreme fatigue.
Heat and cold treatments can temporarily reduce pain and joint swelling. You might try soaking in a warm tub or placing a warm compress or cold pack on the painful joint.
What Are Psoriatic Arthritis Treatments?
Initial medical treatment consists of NSAIDs for your joints and creams or ointments for your skin. In many people, this is enough to control symptoms. A few people may experience worse skin symptoms from the NSAID they are taking. In this case, the doctor will prescribe a different NSAID.
There are three basic types of medical treatments for psoriasis: (1) topical therapy (drugs used on the skin), (2) phototherapy (light therapy), and (3) systemic therapy (drugs taken into the body). All of these treatments may be used alone or in combination.
- Topical agents: Medications applied directly to the skin are the first course of treatment options. The main topical treatments are corticosteroids, vitamin D-3 derivatives, coal tar, anthralin, or retinoids. There isn't one topical drug that is best for all people with psoriasis. Because each drug has specific adverse effects, it is common to rotate them. Sometimes drugs are combined with other drugs to make a preparation that is more helpful than an individual topical medication. For example, keratolytics (substances used to break down scales or excess skin cells) are often added to these preparations. Some drugs are incompatible with the active ingredients of these preparations. For example, salicylic acid (a component of aspirin) inactivates calcipotriene (form of vitamin D-3). On the other hand, drugs such as anthralin (tree bark extract) may require addition of salicylic acid to work effectively.
- Phototherapy (light therapy): The ultraviolet (UV) light from the sun slows the production of skin cells and reduces inflammation. Sunlight helps reduce psoriasis symptoms in some people. If psoriasis is widespread, as defined by more patches than can easily be counted, then artificial light therapy may be used. Resistance to topical treatment is another indication for light therapy. Proper facilities are required for the two main forms of light therapy. The medical light source in a physician's office is not the same as the light sources generally found in tanning salons.
- UV-B: Ultraviolet B (UV-B) light is used to treat psoriasis. UV-B is light with wavelengths of 290-320 nanometers (nm). (The visible light range is 400-700 nm.) UV-B therapy is usually combined with one or more topical treatments. UV-B phototherapy is extremely effective for treating moderate to severe plaque psoriasis. The major drawbacks of this therapy are the time commitment required for treatments and the accessibility of UV-B equipment. New UVB lasers are also available for the treatment of localized plaques of psoriasis.
- The Goeckerman regimen uses coal tar followed by UV-B exposure and has been shown to cause remission in many patients. Patients may complain of the strong odor when coal tar is added.
- In the Ingram method, the drug anthralin is applied to the skin after a tar bath and UV-B treatment.
- UV-B therapy is usually combined with the topical application of corticosteroids, calcipotriene (Dovonex), tazarotene (Tazorac), or creams or ointments that soothe and soften the skin.
- PUVA: PUVA is the therapy that combines a psoralen drug with ultraviolet A (UV-A) light therapy. Psoralen drugs make the skin more sensitive to light and the sun. Methoxsalen is a psoralen that is taken by mouth several hours before UV-A light therapy. UV-A is light with wavelengths of 320-400 nm. Many patients report relief of disease symptoms with 20-30 treatments. Therapy is usually given two to three times per week on an outpatient basis, with maintenance treatments every two to four weeks until remission. Adverse effects of PUVA therapy include nausea, itching, and burning. Long-term health complications include increased risks of sensitivity to the sun, sunburn, skin cancer, and cataracts.
- Systemic agents (drugs that spread throughout the body): These drugs are generally started only after both topical treatment and phototherapy have failed. Systemic agents may be considered for active psoriatic arthritis.
In some cases, your health care provider may inject your joint with a steroid cortisone medication to relieve inflammation.
What Are Topical Psoriatic Arthritis Medications?
In addition to NSAIDs, your doctor may prescribe other psoriasis medications. Medications applied directly to the skin are the first course of treatment options. The main topical treatments are corticosteroids, vitamin D-3 derivatives, coal tar, anthralin, or retinoids. Generic drug names are listed below with examples of brands in parentheses.
- Vitamin D: Calcipotriene (Dovonex) is a form of vitamin D-3 and slows the production of excess skin cells. It is used in the treatment of moderate psoriasis. This cream, ointment, or solution is applied to the skin two times a day. Oral vitamin D is also recommended for both patients with psoriasis and those with psoriatic arthritis.
- Coal tar: Coal tar (DHS Tar, Doak Tar, Theraplex T) contains literally thousands of different substances that are extracted from the coal carbonization process. Coal tar is applied topically and is available as shampoo, bath oil, ointment, cream, gel, lotion, ointment, paste, and other types of preparations. The tar decreases itching and slows the production of excess skin cells.
- Corticosteroids: Clobetasol (Temovate), fluocinolone (Synalar), and betamethasone (Diprolene) are commonly prescribed corticosteroids. These creams or ointments are usually applied twice a day, but the dose depends on the severity of the psoriasis.
- Tree bark extract: Anthralin (Dithranol, Anthra-Derm, Drithocreme) is considered to be one of the most effective antipsoriatic agents available. It does have potential to cause skin irritation and staining of clothing and skin. Apply the cream, ointment, or paste sparingly to the patches on the skin. On the scalp, rub into affected areas. Avoid the forehead, eyes, and any skin that does not have patches. Do not apply excessive quantities.
- Topical retinoid: Tazarotene (Tazorac) is a topical retinoid that is available as a gel or cream. Tazarotene reduces the size of the patches and the redness of the skin. This medicine is sometimes combined with corticosteroids to decrease skin irritation and to increase effectiveness. Tazarotene is particularly useful for psoriasis of the scalp. Apply a thin film to the affected skin every day or as instructed. Dry skin before using this medicine. Irritation may occur when applied to damp skin. Wash hands after application. Do not cover with a bandage.
What Are Systemic Psoriatic Arthritis Medications?
Systemic medications (those taken by mouth or injection)
- Psoralens: Methoxsalen (Oxsoralen-Ultra) and trioxsalen (Trisoralen) are commonly prescribed drugs called psoralens. Psoralens make the skin more sensitive to light. These drugs have no effect unless carefully combined with ultraviolet light therapy. This therapy, called PUVA, uses a psoralen drug with ultraviolet A (UV-A) light to treat psoriasis. This treatment is used when psoriasis is severe or when it covers a large area of the skin. Psoralens are taken by mouth several hours before PUVA therapy or sunlight exposure. They are also available as creams, lotions, or in bath soaks. More than 85% of patients report relief of disease symptoms with 20-30 treatments. Therapy usually is given two to three times per week on an outpatient basis, with maintenance treatments every two to four weeks until remission. Adverse effects of PUVA therapy include nausea, itching, and burning. These drugs cause sensitivity to sunlight, risk of sunburn, skin cancer, and cataracts.
- Methotrexate (Rheumatrex): This antirheumatic drug is used to treat plaque psoriasis or psoriatic arthritis. It suppresses the immune system and slows the production of skin cells. Methotrexate is taken by mouth (tablet) or as an injection once per week. Women who are planning to become pregnant or who are pregnant should not take this drug. The doctor will order blood tests to check the blood cell count and kidney and liver function on a regular basis while on this medicine.
- Etanercept (Enbrel): This is the first biologic drug approved for treating psoriatic arthritis. It is a manmade protein that works with the immune system to reduce inflammation. Etanercept is given as an injection. The drug can be injected at home. Rotate the site of injection (thigh, upper arm, abdomen). Do not inject into bruised, hard, or tender skin. Enbrel affects the immune system, and individuals with significant infections are not to take this drug. It is rarely associated with heart failure.
- Adalimumab (Humira): The FDA approved this drug in 2005 for reducing symptoms of active arthritis in psoriatic arthritis. It is self-administered as an injection every two weeks. Individuals with active infections are not able to take this drug. It suppresses the immune system. It is rarely associated with heart failure.
- Infliximab (Remicade): This drug was also approved in 2005 for psoriatic arthritis. The drug must be given as a two-hour intravenous (into the vein, IV) infusion. Initially, the drug is given three times within six weeks, and then it may be administered every eight weeks. Side effects are similar to adalimumab and etanercept. It suppresses the immune system and individuals with significant infections are not to take this drug. It is rarely associated with heart failure.
- Cyclosporine (Sandimmune, Neoral): This drug suppresses the immune system and slows the production of skin cells. Cyclosporine is taken by mouth once a day. The doctor will order tests to check your kidney and liver function and levels of cyclosporine in your blood while you are on this medicine. Cyclosporine may increase the risk of infection or lymphoma, and it may cause high blood pressure.
- Ustekinumab (Stelara): This injectable biologic medication treats severe plaque psoriasis and psoriatic arthritis with or without methotrexate. There is an increased risk of infections while taking ustekinumab.
- Certolizumab pegol (Cimzia) is a TNF-blocker given subcutaneously every month. TNF is a protein that creates inflammation. It may self-administered at home or injected in a physician's office or infusion center. It suppresses the immune system, and individuals with significant infections are not to take this drug. It is rarely associated with heart failure and other side effects.
- Apremilast (Otezla) is an oral medicine approved for the treatment of patients with moderate to severe plaque psoriasis for whom phototherapy or systemic therapy is appropriate. It is also used for the treatment of adult patients with active psoriatic arthritis. Apremilast works by inhibiting an enzyme called phosphodiesterase 4 (PDE4 inhibitor). Side effects include increase in depression and gastrointestinal upset such as diarrhea and nausea.
- As of March 2015, two new medications were on the cusp of FDA approval for patients failing the above.
- Secukinumab (Cosentyx) is a subcutaneously injected biologic medication that is targeted against a chemical messenger that is important in the inflammation of the skin in psoriasis and the joints in psoriatic arthritis. The chemical messenger that secukinumab selectively blocks is called interleukin 17 (IL-17). The most common side effects are nasopharyngeal inflammation, diarrhea, and upper respiratory tract infections.
Psoriatic Arthritis Surgery
In one study, 7% of people with psoriatic arthritis needed surgical treatment. If psoriatic arthritis affects one particular joint severely and over a long period, that joint may be surgically treated. Joint replacement is occasionally necessary.
Other Therapy for Psoriatic Arthritis
Conventional therapy for psoriasis has been tested with clinical trials. The FDA has approved conventional drugs for the treatment of psoriasis. Some look to alternative therapy, diet changes, supplements, or stress-reducing techniques to help reduce symptoms. For the most part, alternative therapies have not been tested with clinical trials, and the FDA has not approved dietary supplements for treatment of psoriasis. However, the National Psoriasis Foundation does discuss some other therapies on their web site. Individuals should check with their doctors before starting any therapy.
Psoriatic Arthritis Diet
Research has shown vitamin D supplementation might improve the arthritis of psoriatic arthritis. There is no other universally effective diet for psoriatic arthritis. There are no particular foods to avoid for those with psoriatic arthritis.
Psoriatic Arthritis Follow-up
If someone has symptoms of psoriatic arthritis, a consultation with a rheumatologist (a physician who specializes in arthritis) can optimize care.
Are There Ways to Prevent Psoriatic Arthritis?
Various medications can cause psoriasis to worsen. Try to avoid these medications to minimize flare-ups. Lithium (Eskalith, Lithobid) and withdrawal from systemic corticosteroids (a steroid treatment that affects the whole body) both are well known to cause flare-ups. Beta-blockers, antimalarial drugs, and NSAIDs may also cause flare-ups.
Additional preventative steps for psoriasis flare-ups include the following:
- Avoiding environmental factors that trigger psoriasis, such as smoking, sun exposure, and stress, may help prevent or minimize flare-ups of psoriasis. Sun exposure may help in many cases of psoriasis and aggravate it in others.
- Alcohol is considered a risk factor for psoriasis in young to middle-aged men. Avoid or minimize alcohol use if you have psoriasis.
- Specific dietary restrictions or supplements other than a well-balanced and adequate diet are unimportant in the management of plaque psoriasis.
What Is the Prognosis for Psoriatic Arthritis?
Psoriatic arthritis tends to alternate between flare-ups and periods of improvement. It leads to joint damage and severe disability in many of the people it affects. Some people may need surgery.
The following factors influence how severe your psoriatic arthritis will be:
- Clinical pattern (see symptoms)
- Symptoms beginning when you are young
- Severity of skin symptoms
- Female sex
- Family history of arthritis
Rarely, complications such as joint dislocations of the neck and leaking of the heart valves may develop.
Psoriatic Arthritis Support Groups and Counseling
Education is one of the foundations for managing this chronic and typically relapsing disorder. People with psoriasis should be familiar with the treatment options in order to make proper informed decisions about therapy. The National Psoriasis Foundation is an excellent organization that provides support to people with psoriasis.
Psoriatic Arthritis Pictures
Psoriatic arthritis. Severe deformity of the joints at the ends of the fingers. Severe psoriatic arthritis involving the finger joints. Swelling and deformity of the hand joints in a patient with psoriatic arthritis. Psoriatic arthritis involving the hand joints. Asymmetric (not distributed evenly) psoriatic arthritis. Psoriatic arthritis involving the fingers. X-ray of hand with psoriatic arthritis. Comparison between psoriatic arthritis and rheumatoid arthritis in both hands and feet. Joint damage of arthritis mutilans, a typically psoriatic pattern of arthritis. Psoriatic arthritis, arthritis mutilans.
Klippel, J.H., et al. Primer on the Rheumatic Diseases. New York: Springer, 2008.