In addition to these distinctive patterns of joints, there are other unique features of psoriatic arthritis. These include distinct changes in the tissues surrounding the joints, involvement of tendons, and back pain.
Tissue Swelling
Redness and swelling at the DIP joints is common. Instead of the inflammation being confined to the joints, it can extend to the surrounding tissue such as the tendons, ligaments, and bone. This can result in red, swollen, sausage-like toes or fingers. This sausage-like swelling is called dactylitis.
Tendinitis and Enthesitis
Tendinitis is inflammation of the tendon, while enthesitis refers to inflammation where the tendons attach to the bone. "Tennis elbow" or "heel spurs" are two common painful forms of inflammation at the insertion of a tendon to a bone that occur in people without psoriatic arthritis.
In psoriatic arthritis, tendinitis and enthesitis commonly affect the Achilles tendon or the plantar fascia (heel of the foot). Both can be quite painful, limiting the ability to walk.
Back Pain
In psoriatic arthritis patients, back pain can be caused by inflammation of the spine or lower back (sacroiliac joints). The pain is typically worse in the morning or at night, often waking the patient. Pain and stiffness can improve with activity. Males are more commonly affected than females.
These features may appear alone or in combination, and the characteristics may change over time. Signs and symptoms may vary from patient to patient.
Can Psoriatic Arthritis Affect Any Other Parts of the Body?
In addition to the skin and joints, psoriatic arthritis can affect the eye, urethra, heart, and bowel.
Eye
Up to one-third of patients may have inflammation of the eye, involving the white part of the eye (conjunctivitis) or the pigmented part of the eye (iritis).
Heart
An enlargement (or dilation) of one of the major arteries leading from the heart (aorta) may occur.
Urethra
The urethra is a narrow tube that empties the bladder. Urethritis is an inflammation of the urethra.
What Is the Relationship between the Severity of Psoriasis and Psoriatic Arthritis?
There is no direct, consistent relationship between the severity of the joint and skin diseases. In the past, it was believed that patients with extensive, severe psoriasis would be more likely to have arthritis. However, several recent studies have failed to find such a link either between the extent or the amount of skin disease and joint severity. One exception involves the frequent association of nail abnormalities in patients with involvement of the joints at the ends of the finger or toes.
Many will develop skin lesions before the development or diagnosis of joint disease. Approximately 10-15 percent of affected adults with psoriatic arthritis can present with joint disease first, without the presence of psoriasis skin lesions. To find out more, you can check out Symptoms Of Psoriasis.