Psoriatic arthritis is a form of arthritic joint disease associated with thechronic skin scaling and fingernail changes seen in psoriasis.
Physicians recognize a number of different forms of psoriatic arthritis. In some patients, the arthritic symptoms will affect the small joints at the endsof the fingers and toes. In others, symptoms will affect joints on one sideof the body but not on the other. In addition, there are patients whose larger joints on both sides of the body simultaneously become affected, as in rheumatoid arthritis. Some people with psoriatic arthritis experience arthritis symptoms in the back and spine; in rare cases, called psoriatic arthritis mutilans, the disease destroys the joints and bones, leaving patients with gnarled and club-like hands and feet. In many patients, symptoms of psoriasis precede the arthritis symptoms; a clue to possible joint disease is pitting and other changes in the fingernails.
Most people develop psoriatic arthritis between ages 35-45, but it has been observed earlier in adults and children. Both the skin and joint symptoms willcome and go; there is no clear relationship between the severity of the psoriasis symptoms and arthritis pain at any given time. It is unclear how commonpsoriatic arthritis is. Recent surveys suggest that between 1 in 5 people and 1 in 2 people with psoriasis may also have some arthritis symptoms.
The cause of psoriatic arthritis is unknown. As in psoriasis, genetic factorsappear to be involved. People with psoriatic arthritis are more likely thanothers to have close relatives with the disease, but they are just as likelyto have relatives with psoriasis but no joint disease. Researchers believe genes increasing the susceptibility to developing psoriasis may be located on chromosome 6p and chromosome 17, but the specific genetic abnormality has notbeen identified. Like psoriasis and other forms of arthritis, psoriatic arthritis also appears to be an autoimmune disorder, triggered by an attack of thebody's own immune system on itself.
Symptoms of psoriatic arthritis include dry, scaly, silver patches of skin combined with joint pain and destructive changes in the feet, hands, knees, andspine. Tendon pain and nail deformities are other hallmarks of psoriatic arthritis.
Skin and nail changes characteristic of psoriasis with accompanying arthriticsymptoms are the hallmarks of psoriatic arthritis. A blood test for rheumatoid factor, antibodies that suggest the presence of rheumatoid arthritis, is negative in nearly all patients with psoriatic arthritis. X rays may show characteristic damage to the larger joints on either side of the body as well asfusion of the joints at the ends of the fingers and toes.
Treatment for psoriatic arthritis is meant to control the skin lesions of psoriasis and the joint inflammation of arthritis. Nonsteroidal anti-inflammatory drugs, gold salts, and sulfasalazine are standard arthritis treatments, buthave no effect on psoriasis. Antimalaria drugs and systemic corticosteroidsshould be avoided because they can cause dermatitis or exacerbate psoriasis when they are discontinued.
Several treatments are useful for both the skin lesions and the joint inflammation of psoriatic arthritis. Etretinate, a vitamin A derivative; methotrexate, a potent suppresser of the immune system; and ultraviolet light therapy have all been successfully used to treat psoriatic arthritis.
Food allergies/intolerances are believed to play a role in most autoimmune disorders, including psoriatic arthritis. Identification and elimination of food allergens from the diet can be helpful. Constitutional homeopathy can workdeeply and effectively with this condition, if the proper prescription is given. Acupuncture, Chinese herbal medicine, and western herbal medicine can allbe useful in managing the symptoms of psoriatic arthritis. Nutritional supplements can contribute added support to the healing process. Alternative treatments recommended for psoriasis and rheumatoid arthritis may also be helpfulin treating psoriatic arthritis.
The prognosis for most patients with psoriatic arthritis is good. For many the joint and other arthritis symptoms are much milder than those experienced in rheumatoid arthritis. One in five people with psoriatic arthritis, however,face potentially crippling joint disease. In some cases, the course of the arthritis can be far more mutilating than in rheumatoid arthritis.
There are no preventive measures for psoriatic arthritis.