Former ‘NSYNC member Lance Bass recently revealed that he has been living with psoriatic arthritis for the past 5 years. In an interview with People magazine, Bass said: “I had symptoms before, but you know, I kind of just dealt with it, not knowing exactly what it was. I was a dancer my whole life, so I just figured it was because of dancing… It definitely started in my shoulders and then in my knees. And again, to me, that was just such a sign of dancer pain, so I just thought it was completely normal, totally ignoring the signs.” Bass had previously noticed patches of psoriasis on his scalp.
Bass is grateful for getting a diagnosis and being able to get it under control with a combination of healthy diet and exercise. This is especially true now that he is a father of twins, Violet Betty and Alexander, whom he welcomed with his husband, Michael Turchin, via a surrogate last year: “My shoulders were the main problem for me, and if I would’ve had kids five years ago, I don’t even know if I would’ve been able to feed my kids and hold them in a certain way because you use your shoulders so much. I’m glad I got that under control before the kids came so that I can actually hold them without being in such excruciating pain.”
Bass is now trying to raise awareness about the symptoms of psoriatic arthritis. To that end, he partnered with Amgen (maker of psoriatic arthritis drug apremilast [Otezla]) and created a TikTok-like video with a dance to help others connect their symptoms with psoriatic arthritis. (It should be noted that Bass is not an apremilast patient.)
What is Psoriatic Arthritis?
Psoriatic arthritis is a chronic inflammatory arthritis associated with the skin condition psoriasis. It is most common in adults, affecting men and women equally. According to the National Psoriasis Foundation, more than 8 million people in the U.S. have psoriasis. An estimated 30% of people with psoriasis also develop psoriatic arthritis.
In the majority of patients with psoriatic arthritis, psoriasis precedes the onset of arthritis with skin disease occurring 7-8 years before arthritic symptoms.
The etiology of pathogenesis of psoriatic arthritis is not fully understood but is believed to be a complex interaction of genetic and environmental factors. This results in immune-mediated inflammation involving the skin and joints and, on occasion, other organs.
One-third to one-half of those with psoriatic arthritis have a first degree relative with psoriasis or psoriatic arthritis. Genes associated with psoriatic arthritis include those in the HLA region and also non-HLA genes involved in immune activation and inflammation, including intracellular signaling, cytokine expression, signaling, and T cell effector function. Several environmental factors and features of psoriasis have been incriminated in psoriatic arthritis, including infections (both bacterial and viral) and trauma.
Symptoms of Psoriatic Arthritis
Symptoms of psoriatic arthritis vary greatly from person to person. They may include:
- Scaly, inflamed patches of skin characteristic of psoriasis, often on the scalp, elbows, or knees; typical psoriatic scales are whitish-silver and develop in thick, red patches; on darker skin tones, they may appear as purplish brown with gray scales
- Joint stiffness, pain, and swelling of one or more joints; the joints of the spine can be affected as well, leading to stiffness in the neck, lower back, and hips; joint stiffness is often worse in the morning or after resting
- Fatigue, or feeling tired often or having a lack of energy
- Tenderness in entheses, areas where tendons or ligaments attach to bones; the back of the heel and sole of the foot are commonly affected spots
- Painful, sausage-like swelling of a whole finger or toe (dactylitis)
- Nail changes, such as pitting or crumbling; nails can also separate from the nail bed
- Eye inflammation, especially uveitis, inflammation of the middle layer of the eye; this condition can cause eye pain, redness, and blurry vision, which must be treated promptly to avoid vision loss
- Inflammatory bowel disease, which causes inflammation in the digestive tract, occurs in some people
Joint involvement has been classified into five subtypes:
- Oligoarticular arthritis, which is asymmetric and involves less than five small or large joints
- Polyarticular arthritis, which is usually symmetric and presents similar to rheumatoid arthritis but may involve the distal interphalangeal (DIP) joints
- Distal arthritis, signified by prominent involvement of the DIP joints
- Arthritis mutilans, characterized by a severe destructive joint disease with deformities, especially in hands and feet
- Spondyloarthritis pattern, with sacroiliitis and spondylitis (this may occur with or without peripheral joint disease)
Diagnosis
There is no definitive test for psoriatic arthritis. The diagnosis is often made in patients who have both psoriasis and inflammatory arthritis in one of the typical patterns listed above. In addition, the majority of patients with psoriatic arthritis have a negative rheumatoid factor (RF) as well as negative anti-cyclic citrullinated peptide antibodies (anti-CCP antibodies). However, various studies have shown positive rheumatoid factor in about 2% to 10% of patients with a diagnosis of psoriatic arthritis, and approximately 5% are positive for anti-CCP antibodies.
Characteristic features of psoriatic arthritis — a combination of bone destruction with bone production — may be seen on radiography, and would be seen as erosive changes, gross joint destruction, joint space narrowing, and “pencil-in-cup” deformity.
Treatment
As the severity and clinical manifestations of psoriatic arthritis are diverse, the treatment of psoriatic arthritis for any individual patient should be guided by disease severity, degree of joint damage, the extent of extra-articular disease, patient preference, and other co-morbidities.
Non-pharmacologic therapies include physical therapy, occupational therapy, exercise programs, and smoking cessation. Weight reduction is also an important step, not only to decrease weight on the affected joints, but also because obesity and metabolic syndrome may lessen the treatment response to disease-modifying antirheumatic drugs (DMARDs) and/or biologic agents.
Mild arthritis may be treated with non-steroidal anti-inflammatory drugs (NSAIDs). Those with moderate to severe arthritis are usually treated with conventional disease-modifying antirheumatic drugs (DMARDs). The role of DMARDs is to preserve joints by blocking inflammation. The most common are methotrexate, sulfasalazine (Azulfidine), hydroxychloroquine, and leflunomide (Arava).
A second category of DMARDs are called biologic and/or targeted DMARDs. They are produced using recombinant DNA techniques. There are several types of biologics which target a specific type of molecule involved. These include:
- Tumor necrosis factor (TNF) inhibitors, such as etanercept (Enbrel), adalimumab (Humira), infliximab, certolizumab pegol (Cimzia), and golimumab (Simponi)
- Biologics that target other molecules, including abatacept (Orencia), which blocks communication between inflammatory cells by attaching to their surface, and rituximab (Rituxan), which targets CD20 surface antigen
- Interleukin inhibitors, such as tocilizumab (Actemra), sarilumab (Kevzara), and anakinra (Kineret)
- Kinase inhibitors, such as tofacitinib (Xeljanz), baricitinib (Olumiant), and upadacitinib (Rinvoq)
Most of the biologics are administered by injection or infusion, but kinase inhibitors are produced by traditional drug-manufacturing techniques and given in pill form. Kinase inhibitors are sometimes referred to as “targeted synthetic DMARDs.”
In general, conventional DMARDs can take a month or more to begin working, while biologics and kinase inhibitors tend to work more rapidly — within 2 weeks for some and 4-6 weeks for others. It is not uncommon for DMARDs to be given in combinations.
Michele R. Berman, MD, is a pediatrician-turned-medical journalist. She trained at Johns Hopkins, Washington University in St. Louis, and St. Louis Children’s Hospital. Her mission is both journalistic and educational: to report on common diseases affecting uncommon people and summarize the evidence-based medicine behind the headlines.