About 30 percent of people with Crohn’s disease will develop arthritis, according to the Crohn’s & Colitis Foundation. This makes arthritis the most common extraintestinal (outside the digestive tract) complication of Crohn’s. And while typically more than half of people with arthritis range in age from 18 to 64 years olds, Crohn’s-related arthritis often happens in people between 25 and 45.

Some research suggests an overlap between Crohn’s disease and other immune-mediated inflammatory diseases, such as psoriatic and rheumatoid arthritis. An analysis published in September 2020 in Wiener Klinische Wochenschrift (the Central European Journal of Medicine) found that people with psoriatic arthritis tended to also have Crohn’s disease or ulcerative colitis. A research review published in June 2020 in BMC Gastroenterology found that people with inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, have a significantly increased risk of rheumatoid arthritis. “It is believed that the chronic inflammation in the intestines or colon can trigger the immune system to start an inflammatory process in the joints or tendons,” says Michael R. Cannon, MD, a rheumatologist with Arthritis Consultants of Tidewater in Virginia Beach, Virginia. High inflammation manifests in both diseases, and one theory is that bacteria may be behind it. Research published in February 2017 in Science Translational Medicine found large amounts of a specific type of E. coli in the feces of people with Crohn’s disease and spondyloarthritis (an arthritis affecting the spine and joints). In the same study, researchers found that the bacteria affected Th17 cells, which mediate inflammatory responses. According to a research review published in October 2019 in the United European Gastroenterology Journal, an imbalance in the gut microbiome affects people with IBD and rheumatoid arthritis, possibly promoting inflammation. More research is needed, though. RELATED: Could a New Diet Focused on Restoring the Gut Microbiome Reduce IBD Symptoms? Variations in genes and proteins may be another cause of increased inflammation. Crohn’s & Colitis UK says that the presence of the HLA-B27 gene is seen more in people in with Crohn’s arthritis. Additionally, at normal levels, a protein known as tumor necrosis factor helps ward off infection. However, overproduction of it may trigger high levels of inflammation.

Types of Arthritis Associated With Crohn’s Disease

While Crohn’s disease increases the risk for arthritis, the Crohn’s & Colitis Foundation says that you’re more likely to develop one of these two specific types: Peripheral Arthritis This condition affects the joints in your arms and legs, including hands, wrists, elbows, knees, ankles, and feet.  It tends to mirror the level of intestinal inflammation seen in Crohn’s. Your doctor may recommend a series of tests — analysis of joint fluid, blood tests, and X-rays — to give an accurate diagnosis of this particular arthritis. If left untreated, the pain can persist for several weeks. Axial Arthritis Also called spondylitis or spondyloarthropathy, this affects the lower spine, joints at the bottom of your back, and hips. It may start months or years before you show any signs of Crohn’s. Without proper treatment, there is a risk of your spinal bones fusing together, leaving you with a limited range of motion. Ankylosing Spondylitis This severe form of arthritis, seen in 2 to 3 percent of people with IBD, inflames the spine, heart valves, lungs, and eyes. Signs of ankylosing spondylitis tend to precede IBD, and it’s more common in men under 30. RELATED: IBD and Ankylosing Spondylitis In some people with joint pain and Crohn’s, the joint problem could be related to medication side effects or intolerance rather than true arthritis, says Jeffry Katz, MD, a professor at Case Western Reserve University School of Medicine in Cleveland.  According to the New York State Department of Health, bone loss occurs most rapidly in the first six months after starting on oral steroids (such as prednisone), which may be taken to manage inflammation. If steroids are used over a long period of time, the accumulating bone loss can lead to premature osteoporosis, subsequent bone decay, fractures, and eventual joint pain. RELATED: The Pros and Cons of Taking Steroids for IBD

Treating and Managing Crohn’s and Arthritis

Arthritis is manageable when you take action to avoid situations that worsen inflammation. The first step in managing Crohn’s arthritis is to tell your doctor about all of your symptoms. “Many people with joint pain and Crohn’s don’t tell their gastroenterologist about their joint problems because they just attribute it to getting older, rather than being a part of the inflammatory disease process,” says Christopher R. Morris, MD, a rheumatologist with Arthritis Associates in Kingsport, Tennessee. Because Crohn’s arthritis often affects younger patients, seeing a rheumatologist might help. Your rheumatologist and gastroenterologist can coordinate your care to better treat both conditions. Given that treatment needs to address both conditions, pain relievers such as aspirin and ibuprofen (Advil, Motrin) that would typically help people with arthritis are not an option for Crohn’s arthritis because they can trigger a flare-up. However, Dr. Morris says that milder drugs such as Azulfidine (sulfasalazine) can help both the gastrointestinal (GI) tract and joints while Lialda (mesalamine) does a better job of treating the GI symptoms than the arthritic symptoms. Additionally, Crohn’s & Colitis Canada says that Celebrex (celecoxib) is a viable option because it has fewer negative side effects on the gut. Some older patients report that their arthritis gets worse in the winter — a phenomenon that may be related to changes in atmospheric pressure, says Neilanjan Nandi, MD, a gastroenterologist and associate professor at Penn Medicine in Philadelphia. In fact, a study published in October 2019 in the journal NPG Digital Medicine found that people reported more chronic pain on days with high humidity, strong winds, and low pressure. Dressing warm and exercising to maintain flexibility is key to keeping symptoms under control during the colder months, Nandi says. Physical therapy or exercise therapy is often part of the plan for arthritis treatment, particularly to help with back pain and to prevent losing range of motion in the joints. Another important part of your treatment plan is exercise, which might reduce pain and strengthen muscles, providing additional joint protection, Dr. Cannon says. Consider these exercises:

StretchingLow-impact aerobic exercise such as an elliptical machine, pool exercises, a stationary bike, yoga, and tai chiStrength training

RELATED: Tips for Pain-Free Exercise with Arthritis Unsure of how to start? A physical therapist can help develop an exercise program for you. Morris cautions against exercising a joint that’s inflamed and notes that overdoing exercise can trigger joint flares. Splitting up tasks, balancing activity with rest, and pacing yourself will help you accomplish more over time. Be sure to discuss your exercise program with your doctor so that you can map out a comprehensive plan to address Crohn’s disease, your degree of arthritis, and any other health problems you’re managing. RELATED: 7 Ways to Work Out if You Have Crohn’s Disease