Psoriatic arthritis is a type of arthritis that develops in some people who experience the skin condition psoriasis. The skin occurs in a constant process of regeneration, and completely replaces itself during the course of a month. New skin cells form underneath the outer layer of older skin. These then sloughs off to expose the newer skin. Psoriasis develops when the regeneration process occurs too quickly-the new skin cells develop faster than they should and the old skin isn’t shed quick enough. This causes scaly red patches of skin to form, known as plaques. These can become very sore and itchy. These psoriasis plaques are commonly found in localized patches on the knees, elbows, tail or head but can be obtained anywhere on the body and can occasionally cover a wider area.
Psoriatic arthritis generally only develops in psoriasis sufferers, although this doesn’t mean that psoriasis sufferers will automatically develop the condition, nor does it mean that persons with the most severe psoriasis symptoms will develop more severe forms of psoriatic arthritis. The condition occurs in around five to ten percent of people with psoriasis. In addition, around fifteen percent of people develop psoriatic arthritis before experiencing the symptoms of psoriasis.
There are five different types of psoriatic arthritis. Each type has its symptoms and treatment.
Symmetric arthritis; this affects the same joints in pairs, on either side of the body; for example both knee joints will be affected. The symptoms resemble a milder form of rheumatic arthritis, although it can occur in more severe forms and cause deformity to the joints. Symmetrical arthritis is the second most common form of psoriatic arthritis and seeks to cause more severe psoriasis symptoms.
Asymmetric arthritis; this tends to affect only a small number of joints, generally less than five, and joints are affected individually instead of in pairs. Although any joint can be affected, it is most common on the fingers and toes, and can lead to a swelling in fingers known as ‘sausage digits’. Asymmetrical arthritis is one of the more common forms of psoriatic arthritis, and is milder and less progressive than other types.
Digital Interphalangeal Predominant (DIP) arthritis; this affects the last joint in the toes and fingers, and can be mistaken for osteoarthritis.
Arthritis mutilans; this is a rare form of psoriatic arthritis, affecting fewer than 5% of sufferers, but can be severe. It can destroy cartilage and bone tissue, and can cause deformity to the hands, feet or spine. It generally occurs in flare ups and subsequent remissions. These are recorded in the symptoms of psoriasis.
Arthritis can cause pain in the joints, tendon, cartilage, and ligaments of the body. Mostly in areas like the carpus, feet, knees, hips, and hands. Osteoarthritis happens when the cartilage in the joints wear down. It commonly affects hands hips, spine, and knees. Rheumatoid arthritis is an inflammatory form and causes severe joint pain and damage because the body immune system is attacking itself. This is called an autoimmune disease. It can affect people of all ages, young children to older adults.
Spondylitis; this is an inflammation of the spinal joints and discs, and can be quite severe, resulting in spinal deformities if not treated. It can also influence the joints and ligaments in the arms and legs. The predominant symptoms include stiffness in the back and neck joints, tenderness and inflammation.
People with psoriatic arthritis may develop more than one of the following types and can show symptoms of several at any one time. This can make diagnosis of one single type more difficult. There are likewise other types of arthritis that sufferers of psoriasis are at risk of developing; these are gout. This causes sudden inflammation in the toes, feet or hands, rheumatoid arthritis, osteoarthritis and Reiter’s Syndrome, which causes arthritis as well as inflammation of the urethra and eyes.
These symptoms can be mild or more severe and can flare up and die down in a similar way to the symptoms of psoriasis. The two conditions can even mirror each other at times. Psoriatic arthritis occurs most often in the finger and toe joints, particularly the end joints, but can affect any joint in the body.
Although there is no cure for psoriatic arthritis, there are a number of treatments available to alleviate the symptoms and avoid further injury to the joints.