In September, the world of entertainment news buzzed with word that Kim Kardashian West tested positive for lupus and rheumatoid arthritis. The star underwent further tests, however, resulting in a diagnosis of psoriatic arthritis instead. While all three autoimmune disorders share some signs and symptoms, psoriatic arthritis is generally considered to have a better prognosis than lupus. That said, the conditions can co-exist and lupus has gotten a reputation for being difficult to diagnose, especially in the absence of the butterfly-shaped rash on one’s cheeks and nose.
“I’m so relieved. The pain is going to come and go sometimes, but I can manage it and this is not going to stop me,” Kardashian said in an article in response to receiving her psoriatic arthritis diagnosis. Her relief at not having lupus is understandable, given that lupus can affect a greater number of organs and systems in the body and is considered to be life-threatening.
Lupus, rheumatoid arthritis and psoriatic arthritis are examples of some conditions that are often considered when an individual is undergoing diagnosis for certain autoimmune diseases, because they share several symptoms and can trigger positive results in the same diagnostic tests. Kim Kardashian received the initial news that she had lupus or rheumatoid arthritis likely due to positive antinuclear antibody (ANA) test results.
An ANA is a blood test ordered when a doctor, usually a rheumatologist, suspects that a patient has a particular kind of autoimmune disorder. This test checks for the existence of autoantibodies, which are produced when a person’s body is, in effect, attacking itself and several areas of the body are affected. A positive ANA test usually indicates that the doctor’s suspicions are confirmed, and then other factors (like medical and family history) need to be considered and more tests done to arrive at a diagnosis.
Psoriatic arthritis is usually diagnosed between the ages of 20 and 50, and occurs in women and men equally. While there is no cure, appropriate and early treatment can help prevent major damage to affected parts of the body.
Genetics of psoriatic arthritis
Psoriatic arthritis appears in a minority of individuals who have already been diagnosed with psoriasis, an autoimmune skin condition with which Kim Kardashian and her mother, Kris Jenner, had already been diagnosed. Psoriatic arthritis affects around 520,000 individuals in the United States alone.
The autoimmune condition is believed to be caused by a combination of genetic factors and environmental triggers. So while some people inherit psoriatic arthritis-related genes, only a subset of those individuals will go on to develop the condition. In these cases, the disease could be triggered by other illnesses or infections, various forms of extreme stress, poor diet, smoking, and so on.
Around 40 percent of psoriatic arthritis patients have one or more close family members with psoriasis or psoriatic arthritis diagnosis, which strongly indicates that the disease is hereditary. Interestingly, recent research has suggested that psoriasis patients who go on to develop psoriatic arthritis have a different genetic profile than those who do not. And the most well-studied of the psoriatic arthritis genes belong to a family of genes called the human leukocyte antigen (HLA) complex, which help the body tell the difference between its own proteins and viral or bacterial proteins.
According to Genetics Home Reference by the U.S. National Library of Medicine, “Variations of several HLA genes seem to affect the risk of developing psoriatic arthritis, as well as the type, severity, and progression of the condition.”
Symptoms and treatment
“I’ve been feeling so tired, so nauseous, and my hands are really getting swollen. I feel like I literally am falling apart. My hands are numb,” Kardashian said on a recent episode of “Keeping Up with the Kardashians.”
These kinds of descriptions are common in all three conditions — lupus, rheumatoid arthritis, and psoriatic arthritis — though each patient presents with a different array of symptoms, and all with varying degrees of severity. The main symptoms of psoriatic arthritis are pain, stiffness, and swelling in affected joints, along with chronic fatigue. Joints near the end of the fingertips and tips of the toes are often affected, as are bones in the spine.
The symptoms of psoriatic arthritis tend to worsen over time, though some patients experience periods of remission when symptoms temporarily improve. Compared to rheumatoid arthritis, psoriatic arthritis is more likely to cause swelling in the smallest joints of the fingers and toes, foot pain (in the heel and/or sole of the foot), and lower back pain caused by inflammation in vertebral joints. Patients with psoriatic arthritis are also more likely to experience symptoms on one side of the body or in different appendages on each side (in other words, it tends to be an “asymmetric disease”), whereas patients with rheumatoid arthritis are more likely to experience symptoms that affect both sides of the body equally (“symmetric disease”).
Most if not all patients with psoriatic arthritis also have psoriasis, an autoimmune condition that causes red, scaly patches of skin that can be itchy, painful and embarrassing. Psoriasis usually precedes the onset of psoriatic arthritis by several years. People with psoriatic arthritis commonly experience fingernail changes, too, such as the formation of a pitted or ridged nail surface, or the nails become separated from the nail beds.
There are several treatment options for psoriatic arthritis, which include nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce inflammation and pain, immunosuppressants to suppress the immune system, disease-modifying antirheumatic drugs (DMARDs) to slow the progression of the disease, and newer medications that minimize the activity of certain enzymes involved in the inflammatory process. Treatment plans may also involve steroid injections administered directly into affected joints, or joint replacement surgery in cases where the disease has significantly progressed.
Kristen Hovet covers genetics, medical innovations and the intersection of sociology and culture. The North Dakota native is based in Vancouver, Canada, where she is working on a master’s degree in health communication at Washington State University. Follow her on her website or Twitter @kristenhovet