Psoriatic Arthritis

Definition

Definition of Psoriatic Arthritis
Psoriatic arthritis is a type of inflammatory arthritis that, according to the National Psoriasis Foundation, will develop in up to 30 percent of people who have the chronic skin condition psoriasis. Psoriatic arthritis is said to be a seronegative spondyloarthropathy and therefore occurs more commonly in patients with tissue type HLA-B27.

Symptoms

Symptoms of Psoriatic Arthritis
Common symptoms of psoriatic arthritis include:

1. Pain, swelling, or stiffness in one or more joints.
2. Joints that are red or warm to the touch.
3. Sausage-like swelling in the fingers or toes, known as dactylitis.
4. Pain in and around the feet and ankles, especially tendinitis in the Achilles tendon or Plantar fasciitis in the sole of the foot.
5. Changes to the nails, such as pitting or separation from the nail bed.
6. Pain in the area of the Sacrum (the lower back, above the tailbone).

Causes

Causes of Psoriatic Arthritis
The exact causes are not yet known, but a number of genetic associations have been identified in a genome-wide association study of psoriasis and psoriatic arthritis including HLA-B27.

Diagnosis

Diagnosis of Psoriatic Arthritis
There is no definitive test to diagnose psoriatic arthritis. Symptoms of psoriatic arthritis may closely resemble other diseases, including rheumatoid arthritis. A rheumatologist (a doctor specializing in diseases affecting the joints) may use physical examinations, health history, blood tests and x-rays to accurately diagnose psoriatic arthritis.

Factors that contribute to a diagnosis of psoriatic arthritis include:

1. Psoriasis in the patient, or a family history of psoriasis or psoriatic arthritis.
2. A negative test result for Rheumatoid factor, a blood factor associated with rheumatoid arthritis.
3. Arthritis symptoms in the distal Interphalangeal articulations of hand (the joints closest to the tips of the fingers). This is not typical of rheumatoid arthritis.
4. Ridging or pitting of fingernails or toenails (onycholysis), which is associated with psoriasis and psoriatic arthritis.
5. Radiologic images indicating joint change.

Treatment

Treatment of Psoriatic Arthritis
The underlying process in psoriatic arthritis is inflammation, therefore treatments are directed at reducing and controlling inflammation. Milder cases of psoriatic arthitis may be treated with NSAIDS alone; however there is a trend toward earlier use of Disease-modifying antirheumatic drugs or biological response modifiers to prevent irreversible joint destruction.

Nonsteroidal Anti-Inflammatory Drugs: Typically the medications first prescribed for psoriatic arthritis are NSAIDs such as ibuprofen and naproxen followed by more potent NSAIDs like diclofenac, indomethacin, and etodolac. NSAIDs can irritate the stomach and intestine, and long-term use can lead to gastrointestinal bleeding. Other potential adverse effects include damage to the kidneys and cardiovascular system.
Disease-Modifying Antirheumatic Drugs: Rather than just reducing pain and inflammation, this class of drugs helps limit the amount of joint damage that occurs in psoriatic arthritis. Most DMARDs act slowly, and may take weeks or even months to take full effect. Drugs such as methotrexate or leflunomide are commonly prescribed; other DMARDS used to treat psoriatic arthritis include ciclosporin, azathioprine and sulfasalazine. These immunosuppressant drugs can also reduce psoriasis skin symptoms, but can lead to liver and kidney problems and an increased risk of serious infection.
Biological Response Modifiers: Recently, a new class of therapeutics called biological response modifiers or biologics has been developed using recombinant DNA technology. Biologic medications are derived from living cells cultured in a laboratory. Different from the traditional DMARDS that impact the entire immune system, biologics target specific parts of the immune system. They are given by injection or intravenous (IV) infusion.

Biologics prescribed for psoriatic arthritis are TNF-a inhibitors, including infliximab, etanercept, golimumab, certolizumab pegol and adalimumab.

Biologics may increase the risk of both minor and serious infections. More rarely, they may be associated with nervous system disorders, blood disorders or certain types of cancer.

Other Treatments: Doctors may use joint injections with corticosteroids in cases where one joint is severely impacted. In psoriatic arthritis patients with severe joint damage orthopedic surgery may be implemented to correct joint destruction, usually with use of a joint replacement. Surgery is effective for pain alleviation, correcting joint disfigurement, and reinforcing joint usefulness and strength.

Prognosis

Prognosis of Psoriatic Arthritis
The disease is often mild and affects only a few joints. A few people will have severe psoriatic arthritis in their hands, feet, and spine that causes deformities.

Prevention

Prevention of Psoriatic Arthritis
There is no known prevention.