Psoriasis itself is a skin disease causing itchy, scaly rashes and crumbling nails. The cause of psoriasis is still unknown but specialists do know that it is largely affected by the immune system and genetics. Men and women are equally affected, as well as all races and all ages, unlike many other diseases.
However according to the Annals of Rheumatic Disease, between 6 and 42 percent of people who have psoriasis will also develop a form of inflammatory arthritis called psoriatic arthritis (PsA). Like psoriasis, PsA is an autoimmune disease, meaning it occurs when the body’s immune system mistakenly attacks healthy tissue, in this case the joints and skin. The faulty immune response causes inflammation that triggers joint pain, stiffness and swelling.The inflammation can affect the entire body and may lead to permanent joint and tissue damage if it is not treated early.
Most people with psoriatic arthritis have skin symptoms before joint symptoms. However, sometimes the joint pain and stiffness strikes first. In some cases, people get psoriatic arthritis without any skin changes.
The disease may lay dormant in the body until triggered by some outside influence, such as a common throat infection.
Psoriatic arthritis affects the joints and entheses (the places where tendons and ligaments connect to bone). It can cause pain, fatigue, stiffness and swelling. Left untreated, psoriatic arthritis can result in permanent joint damage. This is why it’s important to get the correct diagnosis when symptoms appear and start treatment as soon as possible.
Diagnosing psoriatic arthritis is not always straightforward and can involve multiple investigation after taking a careful history perhaps including family history Examination of the skin, nails and joints. It is also often necessary to have X-rays, an MRI, an ultrasound as blood tests on their own are not always specific enough.
Psoriatic arthritis can sometimes be incorrectly diagnosed as other types of arthritis such as Rheumatoid arthritis or other conditions. However, psoriatic arthritis has characteristics and unique symptoms that can help your provider reach the correct diagnosis.
These symptoms include:
- Morning stiffness or stiffness after resting
- Nail changes such as the nail separating from nail bed, becoming pitted, changing color or resembling a fungal infection
- Swelling of whole fingers or toes rather than just knuckles (also called dactylitis or “sausage digits”)
- Asymmetric joint symptoms (not the same on the left and right sides of the body)
- Enthesitis (pain and swelling of the entheses or places where tendons and ligaments connect to bone, pronounced en-thi-SAI-tis) that commonly affects areas such as the bottoms of the feet, heels, hips or the spine
The pain, swelling and stiffness associated with psoriatic arthritis can affect any joint in the body, but the condition often affects the hands, feet, knees, neck, spine and elbows.
Treatment for psoriatic arthritis includes drugs such as non steroidal anti-inflammatory drugs (NSAIDs); cortisone injections; disease-modifying anti-rheumatic drugs (DMARDs) that act by altering the underlying disease rather than treating symptoms. These reduce pain, swelling and stiffness over a period of weeks or months by slowing down the disease and its effects on the joints. There are also biological treatments - a newer form of treatment for psoriatic arthritis which work by stopping particular chemicals in the blood from activating your immune system to attack the lining of your joints.
For more information about psoriatic disease, visit the National Psoriasis Foundation website at www.psoriasis.org