What is it Psoriatic Arthritis?

Psoriatic Arthritis is defined as an inflammatory condition of the joints (arthritis) associated with Psoriasis. Since in these cases, usually the rheumatoid factor test is negative, Psoriatic Arthritis is called as a sero-negative arthritis. Practically, in addition of all the symptoms of Rheumatoid arthritis, Psoriatic Arthritis also has psoriasis.

Psoriatic Arthritis is an autoimmune disease and it affects the ligaments, tendons, fascia, and joints.

Psoriasis is an obstinate skin condition in which red patches of various sizes develop on the skin that is covered with dry, silvery scales.

In psoriasis the skin becomes inflamed and red eruptions appear on the surface of the skin that begins to itch excessively. These areas form thickened areas (plaques) that are covered with silvery scales over the reddened lesions. The skin at the joints may crack.

Psoriasis most often occurs on the elbows, knees, scalp, lower back, palms, and soles of the feet. However, no area of the skin is exempt, including the genital area. The disease may also affect the fingernails and toenails. About 15 percent of people with psoriasis have joint inflammation that produces arthritis symptoms. This condition is called psoriatic arthritis.

When patient's suffering from psoriasis develops pain, swelling and inflammation in the joints, it is termed as psoriatic arthritis.

The Psoriatic Nail

About 50 percent of persons with active psoriasis have psoriatic changes in fingernails and/or toenails. In some instances psoriasis may occur only in the nails and nowhere else on the body. Nail changes in psoriasis fall into general categories that may occur singly or all together:

Psoriasis most often occurs on the elbows, knees, scalp, lower back, palms, and soles of the feet. However, no area of the skin is exempt, including the genital area. The disease may also affect the fingernails and toenails. About 15 percent of people with psoriasis have joint inflammation that produces arthritis symptoms. This condition is called psoriatic arthritis.

• The nail plate is deeply pitted or depressed
• The nail has a yellow to yellow-pink discoloration
• White areas appear under the nail plate. There may be reddened skin around the nail.
• The nail plate crumbles in yellowish patches (onychodystrophy)
• The nail may be entirely lost

Causes of Psoriatic Arthritis

Approximately 40% of patients with psoriasis or psoriatic arthritis have a family history of these disorders in first-degree relatives.

Psoriatic arthritis is associated with an increased frequency of HLA-B7.

Psoriatic arthritis may be triggered by pro-inflammatory cytokines such as Tumor necrosis factor-alpha (TNF-a) and Interleukin IL-1, IL-6, Il-2 and IL-8.

Psoriatic Arthritis is immunologically medicated disease which has some genetic links, which could at times be triggered by long-term emotional stress.

Symptoms of Psoriatic Arthritis

The most common picture is of a patient suffering from Psoriasis starts experiencing pain and stiffness in the joints. The stiffness is most marked in the morning or after rest. The stiffness may be worse in initial movements but may gradually reduce with continuous movements or as the day progresses.

The symptoms may be of varying severity, ranging from mild, moderate or severe. The patient may experience pain in the ankles, knee, elbows or shoulders or the back.

Some times the pain and swelling may be severe and incapacitating, causing restriction in movements, with the affected joint looking, red, hot and inflamed.

Some times only one or two small joints of the finger or toes may be involved, but presenting with swelling of the entire digit, giving them the appearance of a, "sausage".

Psoriatic arthritis can also cause inflammation of the spine (spondylitis) and the sacrum, causing pain and stiffness in the low back, buttocks, neck and upper back. Psoriatic spondylitis is more common in men. Around 50 % of these patients have spondylitis and 50 % suffer from sacroilitis

The back disease is usually slowly progressive with little radiological deterioration as compared with Ankylosing Spondylitis.

Nail changes are commonly seen in psoriatic arthritis. Pitting and ridges are seen in finger and toe nails of 80% of patients with psoriatic arthritis.

Clinical Symptoms:

Psoriatic arthritis may be present with or without obvious skin eruptions, with minimal skin eruptions or with only nail deformity.

Inflammation at the sites where tendons and ligaments attach to the bone is a characteristic of Psoriatic Arthritis. The enthesis is composed of fibrocartilage and collagen and it aides to absorb and dissipate mechanical stress. Psoriatic Arthritis chiefly affects this site, where the tendons and ligaments attach the bones, and here, it becomes different from Rheumatoid Arthritis.

Patients with psoriatic arthritis can also develop inflammation of the tendons (tendonitis) and around cartilage. Inflammation of the tendon behind the heel causes Achilles tendonitis, leading to pain with walking and climbing stairs. Inflammation of the chest wall and of the cartilage that links the ribs to the breastbone (sternum) can cause chest pain, as seen in costochondritis.