Enteropathic arthritis: joint inflammation linked to Crohn's and colitis

Crohn's disease and ulcerative colitis together make up inflammatory bowel disease (IBD). NICE Clinical Knowledge Summaries explain that both can have extra-intestinal manifestations, meaning effects outside the gut. For Crohn's disease these include abnormalities of the joints, eyes, liver and skin, reported in 20% of people or more, and for ulcerative colitis they include uveitis, inflammatory arthritis, erythema nodosum and pyoderma gangrenosum.

Enteropathic arthritis is the name for inflammatory arthritis of this kind. NICE's guideline on spondyloarthritis describes spondyloarthritis as a group of inflammatory conditions that may be predominantly axial (affecting the spine, as in ankylosing spondylitis) or peripheral (psoriatic arthritis, reactive arthritis and enteropathic spondyloarthritis), and notes that people with predominantly axial disease may have additional peripheral symptoms and vice versa.

This is a different kind of joint problem from the wear-related osteoarthritis. It is an inflammatory process, which is why the pattern of stiffness and the treatments differ, and why it needs recognition as part of IBD care rather than being put down to ageing or overuse.

There is no single presentation. The NHS says in Crohn's disease you may also have symptoms affecting other parts of the body, such as joint pain, sore eyes and skin rashes, and in ulcerative colitis you may get swollen or painful joints during a flare-up, along with a high temperature, red or darker patches of skin, red eyes and mouth ulcers.

NICE's spondyloarthritis guideline describes the wider picture: signs may be musculoskeletal, for example inflammatory back pain, enthesitis (inflammation where a tendon joins a bone) and dactylitis (a swollen sausage-like finger or toe), or extra-articular, for example uveitis and psoriasis. It notes that peripheral presentations can be mistaken for unrelated joint or tendon problems because problems can move around between joints. The NHS describes the axial form, ankylosing spondylitis, as involving back pain and stiffness, pain and swelling elsewhere from arthritis and enthesitis, and extreme tiredness, developing gradually over months or years.

If you have IBD and develop persistent joint pain or swelling, or back pain that is worse at night or in the morning, raise it with your GP or IBD team rather than waiting for a routine review. NICE advises that people with suspected new-onset inflammatory arthritis be referred urgently to a rheumatologist for a spondyloarthritis assessment, and that people with dactylitis, or with enthesitis that is persistent or in multiple sites or accompanied by factors including IBD, are referred too.

Gut symptoms may need urgent help of their own. The NHS says to ask for an urgent GP appointment or get help from NHS 111 for ulcerative colitis symptoms with very bad or bloody diarrhoea, a high temperature, a fast heartbeat or being unable to fart or poo, and to call 999 or go to A&E for severe tummy pain, non-stop bleeding from the bottom, large blood clots or vomiting blood. A hot, swollen single joint with fever should also be assessed urgently.

NICE says not to rule out spondyloarthritis solely on the presence or absence of any individual sign, symptom or test result, and that it can be missed even when it follows an established comorbidity such as IBD. Axial spondyloarthritis may be present in people who are HLA-B27 negative and despite no evidence of sacroiliitis on a plain X-ray.

Assessment is by a rheumatologist, who takes the history of back pain, enthesitis, dactylitis, uveitis, psoriasis, IBD and family history into account and uses imaging and blood tests as appropriate. The NHS notes that in non-radiographic axial spondyloarthritis changes to the spine cannot be seen on an X-ray but can sometimes be seen on an MRI scan. Your gastroenterology team will already hold information about the bowel disease, so ask that the two teams share it.

Treatment aims to control joint inflammation, protect function and fit with the treatment of the gut. NICE's guideline on spondyloarthritis recommends NSAIDs at the lowest effective dose for axial disease, and for peripheral disease considers standard DMARDs, saying the choice should take into account comorbidities such as uveitis, psoriasis and inflammatory bowel disease. Corticosteroid injections or short-term oral steroids may be added to manage symptoms.

Because NSAIDs can interact with bowel disease, the NHS advises people with ulcerative colitis not to take them unless prescribed by a doctor and lists them among possible triggers of flare-ups, and NICE CKS list NSAIDs among Crohn's risk factors. In practice this makes a joint plan between rheumatology and gastroenterology important. NICE also recommends that people with axial disease be referred to a specialist physiotherapist for an individualised structured exercise programme, and NHS guidance on ankylosing spondylitis lists exercises, physiotherapy, painkillers, anti-TNF medicines and other biological therapies.

Some treatments overlap. The NHS lists aminosalicylates, steroids, immunosuppressants and biologics among medicines used for ulcerative colitis, and anti-TNF and other biological therapies among treatments for ankylosing spondylitis, so your specialists may be able to choose medicines that suit both conditions.

NICE says that when discussing a flare management plan people should receive information on how to access care during flares, including a named person to contact such as a specialist rheumatology nurse, self-care such as exercises, stretching and joint protection, pain and fatigue management, potential medicine changes and managing the impact on daily life and work.

The NHS says people with ulcerative colitis should be offered regular check-ups with a GP and specialist team and may be referred to other specialists including a rheumatologist, dietitian, dermatologist or ophthalmologist. NHS guidance on ulcerative colitis advises having vaccinations you are offered, going to bowel cancer screening appointments when invited and exercising regularly. NICE CKS note that follow-up of Crohn's disease includes assessing osteoporosis risk.

On the NHS the route is usually your GP or IBD team, then rheumatology, with shared care for medicines. Some people see a private rheumatologist for faster assessment of new joint symptoms. In both settings the important thing is that the rheumatologist knows about your IBD and the gastroenterologist knows about your joint treatment, because choices of NSAIDs, steroids and biologics interact.