What is psoriatic arthritis?

Psoriatic arthritis is a chronic, inflammatory arthritis that affects about 15% of patients with psoriasis, as well as a small number of people who do not have skin symptoms but have a relative with psoriasis. A patient can also develop psoriatic arthritis before presenting with skin symptoms.

Typical symptoms of psoriatic arthritis (PsA) include swelling, pain and stiffness in any joints.

PsA is an autoimmune disorder in which the immune system confuses the body’s own tissues with an invading organism, which leads to inflammation.

Symptoms can be mild to severe, and the disease can occur intermittently in flares and remission.

Complications can include spondylitis, or PsA in the spine that causes difficulty bending and pain in the neck and spine. Dactylitis is a condition in which the inflammation causes fingers or toes to swell. Enthesitis is a complication with soreness and tenderness in the area where tendons and ligaments connect to bones. In children with PsA, there is also an increased risk of developing uveitis, an inflammatory condition of the eyes.

Diagnosis is made by examination by a rheumatologist. Imaging to identify joint damage may be performed with X-rays, MRI, ultrasound or CT, and bloods tests may rule out other conditions and/or identify markers of inflammation, such as erythrocyte sedimentation rate (ESR) and C-reactive protein.

There is no cure for psoriasis or PsA, but a number of treatments are available. NSAIDs are often the first line of treatment used to help relieve inflammation and pain. Disease-modifying rheumatic drugs (DMARDs) include methotrexate, leflunomide and sulfasalazine and can slow the disease progression and prevent joint damage.

Immunosuppressants include azathioprine and cyclosporine and are usually used to treat disease flares and are usually used in combination with NSAIDs and/or DMARDs. Side effects include increased susceptibility to infection.

Another class of drugs called tumor necrosis factor-alpha (TNF-a) inhibitors can reduce inflammatory effects by suppressing TNF-a activity. Some include monoclonal antibody inhibitors such as Cimzia (certolizumab pegol, UCB), Enbrel (etanercept, Amgen), Humira (adalimumab, AbbVie), Remicade (infliximab, Janssen) and Simponi (golulimumab, Janssen) and others. Many additional drugs in this category are undergoing clinical trials, although some are already approved to treat other autoimmune diseases.

Other treatments range from mild exercise to steroid injections into affected joints and total joint replacement (TJA).

Reference s : www.rheumatology.org, www.mayoclinic.org.