What is Psoriatic Arthritis?

Anyone who has psoriasis and joint pain may have psoriatic arthritis. The signs and symptoms of psoriatic arthritis are:

• The red, inflamed skin of psoriasis.

• Pain and swelling in the joints that is worse in the morning or after rest. Stiffness lessens with activity.

• Sausage-like appearance in the affected fingers and toes (in severe cases.)

• Pitting (small indentations on the nail) or the nails may be pulling away from the nail beds.  Nails may have ridges or a yellowish-orange discoloration.

Psoriatic arthritis is a lifelong condition that causes deterioration, pain, and stiffness in the joints.  Some people experience only joint problems and never develop psoriasis.  About 70% of people who get psoriatic arthritis develop psoriasis first.  Studies show that in these cases, psoriasis usually precedes psoriatic arthritis by about 10 years.  However, a person can develop psoriatic arthritis within a few months of getting psoriasis or decades later.

Psoriatic arthritis most commonly involves the fingers and toes. Joints in the neck, back, knees, ankles, and other areas also may be affected. In addition to being painful and stiff, the involved areas usually feel hot. Affected joints tend to have a purplish discoloration.

Almost 90% of people who develop psoriatic arthritis see nail involvement first. The nails may pull away from the nail bed or develop pitting, ridges, or a yellowish-orange discoloration. Dermatologists urge their patients who have psoriasis that involves the nails to contact them if they experience any joint problems. Joint deterioration can be prevented with treatment.

Early warning signs of psoriatic arthritis include hand pain, foot pain, and "tennis elbow." These early warning signs may be overlooked if psoriasis lesions are not present. Other indications are shoulder, neck, or back pain.

Psoriatic arthritis ranges in severity. It can involve one digit or an entire hand. It can become so severe that it is disabling. According to the National Psoriasis Foundation, about 20% of patients living with psoriatic arthritis have more than five totally damaged joints, which significantly impairs their ability to perform everyday tasks and reduces their quality of life.

Who Gets Psoriatic Arthritis
About 1 million people in the United State are living with psoriatic arthritis, which occurs equally in men and women. Psoriatic arthritis occurs most frequently in people with active psoriasis, especially those who have pustular psoriasis. A higher incidence of psoriatic arthritis is found in people who have psoriatic nails.

Psoriatic arthritis can begin at any age. However, swelling and stiffness in the joints usually first appears between 30 and 50 years of age. People who have psoriasis usually experience skin flare-ups months to years before the joints become stiff and swollen.

Children also can develop psoriatic arthritis. A pediatric form may appear as early as 2 to 4 years of age in girls. A peak time for psoriatic arthritis to occur in both boys and girls is 11 to 12 years of age. In rare cases, the arthritis appears before lesions on the skin.

Psoriatic arthritis may appear in children several years before psoriasis. This can make recognizing psoriatic arthritis difficult, especially if there is no known family history of psoriasis.

Causes
Like psoriasis, psoriatic arthritis is believed to be caused by an abnormality in the immune system. Another similarity is that a "trigger,” such as stress, can cause psoriatic arthritis to develop in a genetically predisposed person.

What to Do if You Have Symptoms
Anyone who has psoriasis or a family history of psoriasis and experiences joint stiffness and swelling should make an appointment to see a dermatologist. Medication can help prevent joint deformities and disability if used early. Without treatment, joint degeneration and destruction can occur, making it painful if not impossible to perform some daily activities.

Joint degeneration can develop quickly and is irreversible. More than 50% of people living with psoriatic arthritis have some limitations. More than 60% lose time from work. If allowed to progress, morning stiffness can last for a few hours.

Diagnosis
The goal is to diagnose psoriatic arthritis in its earliest stages. Diagnosis usually begins with a review of the patient’s medical history and examination of the patient’s skin, joints, and fingernails. Since symptoms resemble those of rheumatoid arthritis, blood and serum tests are often necessary to differentiate it from rheumatoid arthritis and other autoimmune (person’s own immune system develops a reaction against something in the person’s own body) conditions. X-rays are sometimes taken to distinguish psoriatic arthritis from other types of arthritis.

Treatment
Years of research have given dermatologists a better understanding of psoriatic arthritis. Today, new treatments and therapies offer renewed hope to patients with this lifelong condition.

The goals of treatment are:

• Control symptoms

• Inhibit deformities and joint damage

• Prevent disability

No single psoriatic arthritis treatment works for everyone. Instead, the goal is to find the treatment that works best for each patient with the fewest side effects. Dermatologists will often recommend a treatment or a combination of treatments based on the type and severity of the psoriatic arthritis.

Medications used to treat psoriatic arthritis include:

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) can help alleviate pain, swelling, and stiffness in the joints. Some NSAIDs require a prescription. Others can be purchased over-the-counter and include aspirin, ibuprofen, and naproxen sodium.

Disease-Modifying Anti-Rheumatic Drugs (DMARDs) are an option when the pain and swelling from psoriatic arthritis are more severe or there is any sign of joint immobility. These medications are used to control signs and symptoms. Due to the potential for serious side effects, these are only available by prescription and should only be taken following consultation with a physician experienced in treating this condition.

Cyclosporine, methotrexate, and sulfasalazine are some of the DMARDs used to treat psoriatic arthritis. Cyclosporine and methotrexate also can effectively treat psoriasis.

One class of DMARD is the biologics, which are prescription therapies that target a specific part of the immune system to block the effects of the psoriatic arthritis. Some biologics have been shown to not only control symptoms but to slow progression of joint damage. Biologics can be used with other medications.

Most observed side effects from the biologics have been mild. However, long-term side effects are still not known but may include increased risk of malignancy and serious infections due to the ability of the biologics to alter the immune system. These potential side effects are not unique to biologics and have been demonstrated following use of other DMARDs.

Etanercept and infliximab (two biologics) are proving effective for treating both psoriatic arthritis and psoriasis. Etanercept has been approved by the U.S. Food and Drug Administration (FDA) to treat both conditions. Infliximab is FDA-approved to treat the signs and symptoms of active psoriatic arthritis.

In clinical trials, many patients taking etanercept experienced rapid and effective treatment for their skin and joints. Etanercept has shown that it can significantly inhibit joint destruction, bone erosion, and narrowing of the joint spaces.

Clinical trials for infliximab have shown that the drug can effectively clear the skin, reduce swelling in the joints of toes and fingers, as well as decrease inflammation of the tendons and ligaments. Before taking infliximab, a person must be tested for tuberculosis (TB). If TB is detected, it must be treated before infliximab therapy begins. Patients taking infliximab should be closely monitored for signs of infection. If infection begins, infliximab therapy should be stopped.

It is important to remember that no one medication works for everyone. Equally important is the fact that failure of one biologic does not predict that other biologics will not work.

Medication is not the only treatment for psoriatic arthritis. Other therapies that can help people manage the pain include:

Exercise can help patients keep up their strength, improve joint mobility, and control weight. Obesity puts further strain on impaired and inflamed joints.

Physical, occupational, and massage therapy involve physical treatment of the joints, muscles, ligaments, and tendons by a licensed therapist to reduce pain and improve joint function. Splints can be used during physical or occupational therapy to hold joints in place and reduce pain and swelling. In addition, temperature therapy may be used. It may involve soaking in a hot bath or placing an ice pack on painful joints to help reduce pain and swelling.

Surgery can help psoriatic arthritis patients with badly damaged joints by lessening pain and improving movement. However, this option is not necessary for most people with psoriatic arthritis.

Improved Quality of Life
Recent advances are allowing many with psoriatic arthritis to experience remarkable improvements. It is believed that ongoing research will advance current treatments and continue to improve the quality of life for people living with psoriatic arthritis.

References:
American Academy of Dermatology. “Unique Treatments Offer Relief to Nation's One Million Psoriatic Arthritis Patients.” Accessed May 5, 2005.

Gladman, DD. “Psoriatic Arthritis” in Therapy of Moderate-Severe Psoriasis. New York: NY. Marcel Dekker, Inc.; 2003.

National Psoriasis Foundation. Psoriasis and Psoriatic Arthritis: A Treatment Guide for the Health Insurance Industry. 2004.

Strober, BE. “Psoriatic Arthritis: Diagnosis and Management.” Presented at the 63rd Annual Meeting of the American Academy of Dermatology: Focus Session 602. February 2005: New Orleans.

For an overview, visit the AAD pamphlet Psoriasis and Psoriatic Arthritis.

Supported by an educational donation provided by Abbott.