Psoriatic Arthritis

What is it?

Arthritis is a complex family of musculoskeletal disorders consisting of more than 100 different diseases or conditions that destroy joints, bones, muscles, cartilage and other connective tissues, hampering or halting physical movement. Psoriatic arthritis (PsA) is a type of chronic inflammatory arthritis associated with the chronic skin condition psoriasis, which is believed to be an inherited condition. Psoriasis, which affects about 2 percent of the U.S. population, most often causes patches of thick, reddened, irritated skin with flaky, silver-white patches called scales.

Psoriatic arthritis typically appears about 10 years after the onset of psoriasis, which can manifest at any age, though most people are diagnosed between the ages of 15 and 35. The main symptoms of psoriatic arthritis are:

  • painful, swollen joints
  • tenderness where muscles or ligaments attach to bones, particularly the heel and bottom of the foot
  • back pain
  • nail changes such as separating from the nail bed, or becoming pitted or infected-looking
  • morning stiffness
  • general fatigue
  • reduced range of motion
  • redness and pain in tissues surrounding the eyes (conjunctivitis)

What are the effects?

Psoriatic arthritis is an autoimmune disease that for unknown reasons causes the body’s own immune system to turn against itself. Inflammation can occur causing the synovium--tissue that lines the joint capsule and produces synovial fluid, which lubricates the joint and keeps it moving smoothly—to thicken resulting in a swollen joint.

Over time, the synovium invades the cartilage, elastic tissue that covers the ends of the bones in a joint. The cartilage in turn erodes, causing bones to rub together. As the joint weakens, so do its the surrounding structures, such as muscles, ligaments and tendons. Because this joint damage can occur early in the disease process, diagnosing psoriatic arthritis as quickly as possible and treating it properly are important.

How is it diagnosed?

Psoriatic arthritis can develop slowly, with mild symptoms, or onset can be sudden and severe. There is no easy way to diagnose psoriatic arthritis – no definitive lab or physical test exists to pinpoint it. If you have psoriasis and develop joint pain, your best bet is to have a rheumatologist, an internist who specializes in diagnosing and treating arthritis and related diseases, check you out. Many dermatologists and primary care physicians aren’t that familiar with PsA, which can mimic everything from osteoarthritis to rheumatoid arthritis to gout, and early diagnosis and treatment is critical to prevent damage later on. Doctors first look for common signs and symptoms:

  • general fatigue
  • tenderness, pain and swelling over tendons
  • swollen fingers and toes
  • stiffness, pain, throbbing, swelling and tenderness in one or more joints
  • reduced range of motion
  • morning stiffness and tiredness
  • nail changes – for example, the nail separates from the nail bed and/or becomes pitted and mimics fungus infections
  • redness and pain of the eye, such as conjunctivitis

The next step is to conduct a physical exam of your joints and skin. Your doctor may also order a MRI or CT scan to examine joints in greater detail. Or he might take skin, joint fluid or blood samples to rule out other forms of arthritis such as gout or RA.

What are the treatment options?

There is no cure for psoriatic arthritis. The goal of treatment is to reduce joint pain and swelling, preserve joint function, slow or prevent joint damage and control psoriasis on the skin. Treating PsA centers in part on managing the symptoms. Nonsteroidal anti-inflammatory drugs (NSAIDs) do a good job of reducing pain, swelling and inflammation. However, they can cause stomach distress and ulcers. They may increase the risk of heart attack in some people. Oral and injectible corticosteroids control inflammation, but aren’t recommended for frequent or long-term use.

Other drugs address the disease process itself – disease-modifying antirheumatic drugs (DMARDs) are frequently prescribed, as are biologic response modifiers. Your physician may recommend using two or more together. Some medications affect the immune system or have other side effects, making careful monitoring very important. Engaging in physical activity is an important component of treatment because it can limit the pain and swelling of arthritis that results in stiff joints. Heat and cold treatments may be another option.