Researchers found that people who are most likely to experience a delay fall into three main groups: those who are less than 40 years old when their early psoriatic arthritis symptoms appear; those with a higher body mass index (BMI); and those with enthesitis — inflammation where ligaments and tendons attach to bones. Doctors should be aware of this issue, according to Paras Karmacharya, MD, a rheumatologist at the Mayo Clinic College of Medicine in Rochester, Minnesota, and lead author of the study, who discussed the findings via email. “Our study results help to understand some of the factors associated with diagnostic delay in psoriatic arthritis, which could help in earlier diagnosis and management to improve outcomes in high-risk PsA patients,” he writes.
The Importance of Early Diagnosis in Psoriatic Arthritis
Psoriatic arthritis is an autoimmune disease in which the body’s immune system attacks healthy joints and skin, thereby causing inflammation. Typical symptoms in psoriatic arthritis include stiffness, swelling, and pain over tendons or joints. In addition to inflammation in affected joints, PsA also causes systemic inflammation, which affects the entire body. Psoriatic arthritis is associated with an increased risk for chronic diseases such as heart disease, metabolic disease, and depression, according to the Arthritis Foundation. As with other inflammatory arthritis conditions, psoriatic arthritis can lead to joint destruction and eventually result in deformity and loss of function, says Rochelle Rosian, MD, a rheumatologist and director of regional rheumatology at the Cleveland Clinic in Ohio. “The sooner we can identify and treat psoriatic arthritis with a disease-modifying anti-rheumatic therapy, which might include a traditional DMARD or biologic, the sooner we can slow the process of inflammation and destruction,” she says. Not only will earlier psoriatic arthritis diagnosis and treatment mean less damage to the joints over a lifetime, it also means people with the condition will experience less pain and suffering and have fewer limitations in their day-to-day lives, says Dr. Rosian. RELATED: 8 Surprising Ways Psoriatic Arthritis Can Affect Your Health
Most People Waited More than 2 Years for Psoriatic Arthritis Diagnosis
The Mayo Clinic research, which was published in February in the Journal of Rheumatology, included 162 patients from Olmsted County, Minnesota, who were diagnosed with psoriatic arthritis from 2000 to 2017. The average age at symptom onset in the group was 41.5 years, and 46 percent of the group were females. Investigators found that the length of time from the first PsA-related joint symptoms to a diagnosis was anywhere from six months to a little over seven years, with a median of two and a half years. To explore the reasons for the delay, researchers examined several factors and found that sex, education level, smoking status, alcohol intake, psoriasis severity or location, nail involvement, and family history of psoriatic arthritis made no difference in how long it took for people to get a psoriatic arthritis diagnosis. The traits or symptoms that were linked with a delay were being younger or obese, or having enthesitis. Though this study is relatively small, it was well-designed, says Rosian. Still, she points out, “because the only patients included in the study are Mayo patients, the findings might not be representative of a more diverse population.” That being said, the conclusions do make sense and are consistent with what many rheumatologists observe, says Rosian.
Psoriatic Arthritis Joint Symptoms Could Be Misdiagnosed for Several Reasons
One reason younger patients are at risk for a later diagnosis is that it might take them longer to seek treatment. “Younger patients may be more likely to dismiss their symptoms, not report joint symptoms, or be aware of joint inflammation,” notes Dr. Karmacharya. Because enthesitis is not a common symptom of inflammatory arthritis, patients and general practitioners may attribute the pain or swelling to overuse and trauma, he explains. This may be especially likely to happen when only one joint is affected, says Rosian. “For example, enthesitis in the Achilles tendon or the elbow can get diagnosed and treated as a sports injury rather than psoriatic arthritis. Primary care doctors or sports medicine doctors may be only looking at the one joint rather than the whole person,” she says. People with obesity often have other conditions that could potentially explain their joint symptoms, such as osteoarthritis or gout, according to Karmacharya. “Joints symptoms might be dismissed in these cases,” he adds.
Shortage of Rheumatologists May Be Worsening the Problem
Even if a person’s primary care doctor or another physician suspects psoriatic arthritis and makes a referral to a specialist, a shortage of rheumatologists could lead to a delay in diagnosis. “It can be difficult to get an appointment sometimes — that’s a bit of an obstacle for some people,” says Rosian. The 2015 Workforce Study of Rheumatology Specialists found there were 14 percent fewer full-time rheumatologists than would be considered ideal, a problem expected to worsen over time. By 2030, the study projected the number of full-time rheumatologists would decrease from 5,415 to 4,133. During this same time period, the adult patient demand for arthritis care is expected to increase between 25 and 50 percent, mainly due to the growing and aging U.S. population. The researchers calculated that by 2030, the number of rheumatologists will be half of what is considered optimal.
Wouldn’t the Presence of Psoriasis Make Diagnosing Psoriatic Arthritis Easier?
Psoriatic arthritis is related to psoriasis, a visible skin condition that can appear as raised, scaly patches. You would think that doctors would look for psoriatic arthritis in patients with psoriasis who experience joint pain, but that does not appear to be the case. For starters, PsA doesn’t develop in everyone with psoriasis — only about 30 percent of people with the skin condition go on to develop PsA, usually about 10 years after psoriasis first appears, according to the National Psoriasis Foundation. And in some cases, psoriatic arthritis occurs before psoriasis. There are also times when people who develop psoriatic arthritis don’t know they already have psoriasis, says Rosian. “For example, people who have only scalp psoriasis or patches of psoriasis in what we call inverse locations, such as the ears, belly button, or gluteal cleft, may not be aware they have psoriasis. They may be putting up with the skin symptoms or treating them with over-the-counter lotions or steroids,” she says. According to the National Psoriasis Foundation, there’s little connection between psoriasis severity and PsA severity — you can have mild psoriasis and have many joints affected by psoriatic arthritis. It’s also possible for people with psoriasis to have other forms of joint disease such as osteoarthritis and gout, according to Karmacharya.
How Rheumatologists “Build a Case” for PsA
The hard part about diagnosing psoriatic arthritis is that there’s no one test. “Often it involves eliminating other conditions that could mimic psoriatic arthritis — rheumatoid arthritis, the connective tissue diseases, lupus, gout, things like that,” says Rosian. Accurately diagnosing psoriatic arthritis isn’t a simple yes-or-no answer but a process. “We build a case for PsA, which is one of the reasons it’s difficult; you have to put a lot of subjective and objective information together,” Rosian explains. This requires taking a good family medical history and conducting a thorough head-to-toe physical exam. “We look at fingernails and skin, ask about inflammatory eye disease, and try not to miss any clues. Sometimes it’s only when two or three more joints become affected that it becomes apparent that this might be a whole-body systemic inflammation,” says Rosian. RELATED: 12 Medical Tests for Psoriatic Arthritis, Explained
When to Seek Out a Rheumatologist
“We need to do a better job educating people about this [issue]. People should know if they have skin disease and then have joint pain, it could mean psoriatic arthritis,” says Rosian. Although a two-and-a-half-year wait isn’t ideal, Rosian doesn’t believe too much joint damage is likely to occur in that time frame. “Two years is still within a window where it’s not too late to get treatment, though it is a long time to wait for a diagnosis when you’re suffering,” she says. If you’ve had joint pain in two or three joints that you’re trying to treat yourself or if you have stiffness in the morning that lasts an hour or more, this should ramp up your concern. “It’s important to speak to a healthcare provider because there might be something systemic going on,” says Rosian.
