US Pharm. 2022;47(3):15-16.

Chronic Inflammatory Disease

Psoriatic arthritis (PsA) is a chronic, progressive inflammatory disease that affects individuals diagnosed with the skin condition psoriasis. Studies show that up to 30% of patients with psoriasis will develop PsA as a complication. Still, the actual number might be higher given that PsA is often mistaken for other types of arthritis. It affects men and women almost equally, with an average age at onset of 30 to 40 years. In most people, the skin lesions of psoriasis appear before PsA develops. In some individuals, the arthritic symptoms appear simultaneously with the skin disease. In others, arthritis occurs before the skin lesions of psoriasis.

Affects People With Psoriasis

The joint pain, stiffness, and swelling associated with PsA can resemble other arthritic conditions. Still, the underlying cause of PsA is the presence of psoriasis. Psoriasis is a skin disease that manifests as itchy, scaly, red patches on the body—most commonly the scalp, trunk, knees, and elbows. Scientists believe both genetics and environmental factors, such as  infections and physical injury, contribute to the development of psoriasis and PsA. Recent studies have pointed to specific psoriatic risk factors that increase the risk of developing PsA, including having more than three body sites affected by psoriasis. Lesions located on the scalp or between the buttocks seem to increase the risk of PsA.

Diagnosis Is Challenging But Important

Physicians will look for several characteristic symptoms of PsA when making a diagnosis. Pain, swelling, and stiffness commonly occur in the knees, fingers, hips, ankles, and wrists. Painful, sausage-like swelling of a single toe or finger indicates PsA. Lower back pain caused by swelling of the joints between the vertebrae of the spine and foot pain, especially near the back of the heel or on the sole of the foot, can be present in PsA. In addition to the joint pain, changes in the nails, and inflammation of the eye, called uveitis, also indicate PsA. The symptoms of PsA can alternate between flares and remission and can also change in location over time.

PsA looks very similar to other arthritic conditions, making it challenging to diagnose immediately. It is crucial that PsA is diagnosed relatively quickly, as permanent damage to the joints can occur, leading to loss of function, disability, and a significant impact on a person’s quality of life. Additionally, those with PsA are at a higher risk of developing inflammatory bowel disease, cardiovascular diseases (including obesity, hypertension, and type 2 diabetes mellitus), depression, anxiety, and fatty liver disease.

Drug Treatment Can Slow Progression

The past 20 years have provided many new options for managing the symptoms and slowing the progression of PsA. The therapy goals are to reduce symptoms, minimize joint damage, and preserve physical functioning. In addition to medical management, nonpharmacologic therapies, including physical therapy, occupational therapy, exercise programs, and smoking cessation, are often part of the treatment plan. Unfortunately, there is no cure for PsA or psoriasis.

OTC nonsteroidal anti-inflammatory drugs, such ibuprofen and naproxen sodium, can relieve pain and reduce inflammation for people with mild PsA. Side effects can include stomach irritation, heart problems, and liver and kidney damage. A large group of medications known as disease-modifying antirheumatic drugs (DMARDs) is commonly used to treat PsA. These drugs can slow the progression of PsA and save joints and other tissues from permanent damage. Depending on the type of PsA symptoms, location, and severity, physicians may choose one or a combination of synthetic, biologic, or targeted DMARDs. More recently, an oral medication, apremilast (Otezla), was approved for people with mild or moderate PsA. who cannot take DMARDs or biologic agents. All medications used for the treatment of PsA have serious side effects. Those considering them should discuss them thoroughly with a physician or pharmacist. Complete symptomatic relief is achievable, but a significant majority of patients continue to have persistent inflammatory disease.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

To comment on this article, contact rdavidson@uspharmacist.com.