More Than Skin Deep: How Psoriasis Can Affect Bones

People may often assume that psoriasis is “just a skin disease.” But more accurately, it’s an immune-mediated condition — which means the effects of it can go much deeper than the surface of the skin.

Along with an elevated risk for such health conditions as psoriatic arthritis, heart disease, and diabetes, people who’ve had psoriasis for a long time also tend to have an increased risk of weakened bones (osteoporosis) and loss of bone mineral density (osteopenia), according to a review published in March 2022 in the journal Clinical and Experimental Dermatology.

And a review published in November 2020 in the Journal of Clinical Medicine found that people with psoriatic diseases such psoriasis and psoriatic arthritis — a condition that can develop in people with psoriasis, and causes swelling and inflammation in the joints — may be more likely to develop bone fractures than those without the diseases, although the researchers noted this wasn’t necessarily because they had a higher risk for osteoporosis.

Specifically, people with psoriasis produce certain substances called cytokines, including interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a), which are not only responsible for the formation of plaques on the skin but are also involved in the development of osteoporosis, according to the review.

Inflammation plays a big role in driving this link. “People who have a chronic inflammatory disease like psoriasis are more likely to have a loss of bone density over time,” says Christopher Ritchlin, MD, MPH, a rheumatologist at the University of Rochester Medical Center in New York.

Still, the connection between the two diseases can sometimes go overlooked — so much so that many people who have psoriasis aren’t aware that they may also be at an increased risk for osteoporosis. “I think all patients should be aware of it, because it’s a real problem for some people that may not be adequately addressed,” Dr. Ritchlin says.

What to Know About Your Risk for Osteoporosis

However, not everyone with psoriasis will develop osteoporosis, says Ritchlin, in part because osteoporosis is a particularly complicated disease that can have many risk factors.

Of these risk factors, a big one is a person’s sex. According to the latest statistics from the U.S. Centers for Disease Control and Prevention, about 20 percent of women age 50 and older have osteoporosis, compared with just 4 percent of men. The risk also increases with age: About 27 percent of women age 65 and older have osteoporosis, compared with 6 percent of men.

“Postmenopausal women are more likely to have a rapid loss of bone because [they lose estrogen with age, and] estrogen is a major hormone that’s important for maintaining bone density,” Ritchlin says.

People who also have psoriatic arthritis may have a higher risk of osteoporosis. This type of arthritis can also cause pain and stiffness in the spine, which can limit their ability to move. “If you can’t move the spine, that can result in the loss of bone density,” says Ritchlin.

There’s also evidence that genetics may play a role in increasing a person’s risk for osteoporosis, says Adelaide Hebert, MD, a dermatologist with McGovern Medical School at UTHealth Houston. If you have a parent or a sibling who has osteoporosis — including a mother or father who’s had a hip fracture — you may be more likely to develop it too, according to the Mayo Clinic.

4 Ways to Help Prevent Osteoporosis if You Have Psoriasis

What’s good for your overall health is also good for your bones. Here are four things you can do to help reduce your risk for osteoporosis:

1. Exercise regularly.

Exercise — “especially vigorous exercise that’s weight-bearing,” says Ritchlin — can put stress on your bones, thereby helping to strengthen them. This, in turn, can help prevent bone loss.

Weight-bearing exercise refers to any activity that works your bones and muscles against gravity, according to the American Academy of Orthopaedic Surgeons (AAOS). Some weight-bearing exercises include:

• Walking, hiking, jogging, and running
• Dancing
• Playing tennis, basketball, soccer, and volleyball
• Climbing stairs

If you already have some bone loss, talk to your doctor about what you’re able to do. You may want to avoid certain high-impact exercises that involve jumping or twisting. If you’re not able to be as active as you’d like, tell your doctor. He or she may be able to refer you to a physical or occupational therapist, who can help you modify certain exercises.

2. Incorporate strength training.

Just as lifting weights tears down muscle fibers, which helps to build strong muscles, lifting weights also puts stress on your bones, which actually strengthens them over the long-term, according to the AAOS. You don’t have to opt for dumbbells, though — you can use resistance bands or do body-weight exercises like push-ups.

Aim for about two strength-training sessions a week. Three sets of 12 repetitions of the exercise of your choice is the standard for effective strength training, but you can do more or less as you’re able.

3. Get enough vitamin D.

People with psoriasis also tend to be lacking in vitamin D. In fact, one study published in the journal BMC Nutrition in October 2022 found that people with psoriasis had vitamin D levels that were seven times lower than those without it. These low levels were linked to the duration and severity of the study participants’ psoriasis.

It’s not clear whether getting more D will always help protect your bones, says Ritchlin, but if you’re running low in it — meaning, you have levels that are less than 20 nanograms per milliliter (ng per ML) — it’s a good idea to try and get more of it. Your doctor can check your vitamin D levels with a blood test, says Dr. Hebert.

Vitamin D is called “the sunshine vitamin” because the body produces it from sunlight exposure. You can soak up vitamin D by spending about 10 minutes outdoors. Few foods naturally contain vitamin D, but you can find it in fatty fish like salmon and tuna, or consume fortified foods like milk and breakfast cereals according to the National Institutes of Health Office of Dietary Supplements. It’s also found in soy, almond, and oat milks, so you can opt for those if cow’s milk triggers your psoriasis.

4. Ask your doctor if you should take osteoporosis medication.

If you have psoriasis, you may already be taking medication for it — and thus controlling inflammation, which may help protect your bones. Likewise, there are medications available that can help slow down bone loss.

“We’re very fortunate that now we have a number of medications that can help with bone strength,” says Hebert, though she adds that your dermatologist may not be the one to prescribe them. Still, she adds, “we want to take care of the entire patient, even if we don’t manage every aspect of their care.” Your primary care doctor or a rheumatologist might be the one to prescribe osteoporosis medication.