An unlucky 30% of people living with psoriasis eventually develop psoriatic arthritis. This chronic autoimmune condition causes inflammation and swelling in the joints, usually around your fingers and toes. While psoriasis doesn’t always precede it, studies show that the vast majority of folks with psoriatic arthritis had psoriasis for years or even decades before their joint symptoms began.
The mysterious connection between these two conditions is a topic of ongoing study. “Exactly who’s going to get [psoriatic arthritis] is hard to say, but they both appear to be autoimmune conditions where the body is fighting itself,” says Stuart Kaplan, M.D., chief of rheumatology at Mount Sinai South Nassau Hospital in Oceanside, NY and partner at Rheumatology Consultants, LLC. With psoriasis, the immune system is attacking the skin, leading to the characteristic rash. With psoriatic arthritis, the immune system goes for the joints, causing pain, swelling, and stiffness. While both conditions have similar triggers, the symptoms and day-to-day challenges facing patients are distinct.
Now, a new study review in the Journal of the American Academy of Dermatology is shedding light on an intriguing concept: Circumstantial factors like obesity or physical trauma may play a role in psoriasis patients developing psoriatic arthritis. What does this mean? For folks with psoriasis, maintaining a healthy lifestyle (to the extent that you can control) could be key to reducing your likelihood of disease progression into psoriatic arthritis.
What the Research Says
In this review, researchers looked at 16 different studies examining psoriasis patients who develop psoriatic arthritis to try to understand which environmental factors might link the two. They found no evidence that alcohol, smoking, or psychological trauma played a role, but they did find that psoriasis patients with obesity, and those who had a history of physical trauma (like broken bones, major wounds, or other serious injuries), were more likely than others to develop psoriatic arthritis.
This aligns with existing data on psoriatic arthritis and obesity. “We know that epigenetic, lifestyle, and environmental factors play a role in autoimmune diseases,” says Navya Parsa, M.D., a rheumatologist at Columbia Arthritis Center in Columbus, OH. A study in Autoimmunity Reviews found that obesity plays a major role in the onset and progression of autoimmune diseases (including psoriatic arthritis), due to the production of adipokines, fat cells that contribute to chronic inflammation in the body.
Other studies have also looked at body mass index (BMI) and the development of psoriatic arthritis. Dr. Parsa cites one study in Annals of the Rheumatic Diseases that found that people with higher BMIs have a significantly higher risk of developing psoriatic arthritis. “This increased risk of psoriatic arthritis development in obesity can be due to a number of factors, such as the perpetuation of a chronic inflammatory state, physical trauma, and increased weight bearing load on the joints,” she says.
There is also more research to suggest that previous injury or other physical trauma may contribute to psoriatic arthritis onset. Another study in Annals of the Rheumatic Diseases found that patients with psoriasis who experience physical trauma have an increased risk of developing psoriatic arthritis later in life.
What You Can Do
To reduce your personal risk of developing psoriatic arthritis, try putting these practices into play.
- Watch your weight. Dr. Kaplan notes the research on obesity, physical trauma, and psoriatic arthritis still has a long way to go. “These studies are far from conclusive,” he says. “But with that said, it certainly behooves just about everyone with arthritis to keep their weight under control. We know that being overweight does put stress on the joints.” Obesity is bad for your health in more ways than one—and particularly for autoimmune folks, an active life can be your best tool for fighting disease.
- Know your genetic risk. For those with genetic predisposition to psoriatic arthritis, it’s especially critical to pay attention to your weight and your diet. “In general, autoimmune disease tend to run in families, although there’s no way to predict exactly who is going to get it,” Dr. Kaplan says. It is estimated that around 10% of the global population has specific genes that denote a predisposition to psoriasis. If an immediate family member has psoriasis, psoriatic arthritis, or another autoimmune condition, you should consider yourself at elevated risk. “People who are at risk because they have a family member with an autoimmune disease should be even more vigilant about maintaining their general state of health with exercise, good nutrition, [and making] sure they stay at the proper weight,” Dr. Kaplan suggests.
- Do double duty. Luckily, the lifestyle changes that can help reduce psoriasis are the same ones that can help minimize psoriatic arthritis onset and progression. The American Academy of Dermatology recommends that psoriasis patients quit smoking, reduce alcohol intake, maintain a healthy weight (which can be done by working out and eating well), exercise regularly, and maintain a healthy, whole-foods diet. These choices can help reduce your flares and improve the speed and effectiveness of your treatment plan.
- Diversify your workout routine. “My recommendations for those with psoriasis, psoriatic arthritis, or a genetic risk for these diseases is to focus on a heart-healthy lifestyle,” Dr. Parsa says. “This includes weight control with diet and exercise.” She tells her patients to aim for 30 to 40 minutes of exercise three to four times per week, at minimum. This can be aerobic exercise like running or cycling, strength exercise like weightlifting or barre class, or flexibility and stretching exercise like yoga.
- Go for the greens. Your diet can also be your secret weapon for better health. “I also recommend heart-healthy and anti-inflammatory diets,” Dr. Parsa suggests. “These diets avoid red meat, processed meats and foods, refined grains, excess sugar, and trans-fats. A diet with a lot of green-leafy vegetables, white meat, fish, whole grains, and fruits high in antioxidants is ideal.”
- Find your zen. “Stress affects the immune system and has been shown to exacerbate various types of inflammatory arthritis,” explains Dr. Kaplan. There is clinical evidence to suggest that stress plays a role in sending your immune system into overdrive, exacerbating the inflammatory reaction that triggers your flares. “For people who have psoriatic arthritis, stress is only going to make that worse,” Dr. Kaplan says. Try to incorporate practices like meditation, yoga, and daily movement into your life to keep your mental health in tip-top shape.
Ultimately, the best defense is a good offense. While it’s hard to predict your individual likelihood of developing psoriatic arthritis, you can start reducing the damage before it begins. “Unfortunately, we cannot beat our genetics, but we can change our lifestyles,” Dr. Parsa says. Follow your psoriatic-arthritis treatment plan, keep up with your doctor, and take small steps toward a healthier, more functional you.