Arthritis and Down's Syndrome: there's a link
Published on 05 January 2012
It is thought that arthritis is six times more common in children with Down’s Syndrome than in healthy children. Despite this, the time it takes to for them to be diagnosed is considerably longer. Arthritis Research UK is now funding research to try and improve the situation. Jane Tadman reports.
Youngsters born with the genetic disorder Down’s Syndrome face many problems from the very beginning. As well as learning difficulties, they also have a higher chance of developing other conditions such as congenital heart disease, sight and hearing problems, and Alzheimer’s.
There’s another condition that should be added to that list. As many as two per cent of all Down’s youngsters have an inflammatory form of arthritis similar to juvenile idiopathic arthritis (JIA), called Down’s arthropathy. (Many doctors, in fact, think it is JIA, just occurring much more often in these children.) This may be six times more common than arthritis in healthy children.
In fact, according to pilot research carried out by Maureen Todd, a clinical research nurse in paediatric rheumatology at the Royal Hospital for Sick Children at Yorkhill’s department of child health in Glasgow, that figure could be even higher.
“Our pilot study showed that health professionals often fail to diagnose arthritis in children with Down’s Syndrome,” explains Maureen. “On average it took two years from the onset of symptoms to diagnosis, in stark contrast to the four months it took for diagnosis of juvenile idiopathic arthritis in otherwise healthy children.
“This highlights a need for improved education of joint assessments in these children. The routine health checks these children already receive are an ideal opportunity to target education and to make sure that arthritis is picked up at an early stage.”
Arthritis Research UK has now awarded Maureen a Barbara Ansell fellowship in paediatric rheumatology to take her work further. (The Barbara Ansell fellowship was set up using an endowment from the late, legendary paediatric rheumatologist Dr Barbara Ansell, who devoted her life to improving the lives of children with arthritis.)
So why are there such difficulties in picking up arthritis in Down’s youngsters? Most are already in the healthcare system because of their complex physical needs. Maureen has a couple of theories.
“Arthritis doesn’t seem to be considered very early on in Down’s Syndrome children because they are prone to other chronic musculoskeletal conditions such as joint hypermobility, low muscle tone, dysplasia of the hips, and instability of the neck joints,” she says.
Another reason is that children with Down’s don’t appear to express pain in the same way that other children do. And because they fail to mention it, even though their joints may be visibly affected, it seems to be overlooked by the medical profession.
The reasons why Down’s children are more prone to arthritis are complex. “There is more autoimmune disease in these youngsters, and they’re more prone to leukaemia,” explains Maureen. The type of arthritis they get is very similar to psoriatic arthritis in its development, which she plans to investigate further as part of her fellowship.
After identifying Down’s children in Glasgow via community paediatricians, she is seeing affected youngsters with a whole spectrum of disability aged between two and 16, in clinics at Yorkhill. The aim is to find out more about what types of arthritis develop, how severe it is and how many joints it affects, as well as the prevalence of other musculoskeletal disorders.
Maureen is examining their joints, and, with podiatrist Gordon Watt, examines their feet, performs weight, height and arm span and other tests, and looks at their muscle tone. Their parents fill in questionnaires about their background and family history.
The youngsters are then offered a referral to see paediatric rheumatologist, and former Arthritis Research UK senior lecturer, Dr Janet Gardner Medwin, who is supervising Maureen’s fellowship.
Maureen is planning to hold focus groups involving children and their parents, and also to target school nurses who regularly see Down’s Syndrome children to raise their awareness of the links between the condition and arthritis. And, importantly, she will look at the barriers that health professionals face in identifying joint problems in routine care.
She will then develop a targeted educational package aimed at all health professionals that deal with Down’s, and also families, so that children can be diagnosed – and treated – earlier. There are also plans for a larger UK-wide project, helping to identify cases of arthritis in children with Down’s, leading to future clinical trials.
“Chris’s is a disaster story from the point of view of his joints, but a brilliant story in terms of human endeavour.” – Janice Houston
Janice Houston’s son Christopher, who has Down’s Syndrome, had arthritis for four years before he was eventually diagnosed. From the age of 11, when his ankles started to turn in and he became knockkneed, until his elbows and knees started swelling up and he began to physically slow down, give up football, and once simply sitting down in the middle of the supermarket because he couldn’t walk any further, when he was 14. But throughout he never complained of being in any pain and always told doctors that he was fine, even when he developed a distinct limp.
Janice, a senior nurse manager, knew her way around the health system and had an excellent relationship with her son’s paediatrician, but even she spent years hitting her head against a brick wall, trying to get the medical profession to accept that there was something wrong with Chris – as well as Down’s Syndrome.
She is still furious with one particular orthopaedic surgeon. He didn’t bother to x-ray Chris and asked him to stand on his tiptoes. On finding that his joints were aligned when standing on his tiptoes, even though, like most people, Chris doesn’t actually walk on his tiptoes, he rather dismissively told Janice: “Oh, well, he’s got Down’s Syndrome,” as if to say ’what would you expect?’ A second orthopaedic surgeon then misdiagnosed Chris with multiple epiphyseal dysplasia, for which there was no treatment, after x-raying the youngster.
Chris was finally seen by paediatric rheumatologist Dr Gardner Medwin at Yorkhill, who diagnosed him straight away. However, despite being started on medication – steroids, then sulphasalazine and methotrexate, and a drug trial of etanercept - his condition hasn’t responded particularly well to treatment. Another anti-TNF therapy is being considered.
With the support of Janice and dad Danny, Chris went to mainstream school and left school at 18 with qualifications. Now 22, he works in office administration in the Greater Glasgow and Clyde learning difficulties team. He still lives at home, but enjoys a level of independence, and has many friends and interests. Says Janice: “Chris’s is a disaster story from the point of view of his joints, but a brilliant story in terms of human endeavour.” Unfortunately he has recently developed epilepsy, and Crohn’s disease, although both are well-controlled by medication.
He now attends the adult rheumatology/ orthopaedic clinic at the Southern General Hospital in Glasgow, every three months.
“Chris isn’t in pain although his joints are horrific,” says Janice. “He describes his knees as ‘tickly’. He might need early knee replacement but as he’s not in pain we’re leaving it as long as possible – as long as he can walk. Chris doesn’t care how he looks!”
Janice has been happy with Chris’s care since he was diagnosed with arthritis, but her beef is what happened before that. “If we hadn’t have been his parents, pushing all the time, he wouldn’t be diagnosed yet,” she says.
“Apparently it’s well known that youngsters with Down’s develop secondary conditions in their teens, but the only thing he was checked for was his thyroid, nothing else. People with learning difficulties are already disadvantaged and he was definitely discriminated against. The older doctors in particular took the view that we had to lower our expectations for him because he had Down’s Syndrome. We need more recognition that children with this condition are at increased risk of getting arthritis.”
Janice is hopeful that Maureen Todd’s research may kick-start some muchneeded changes within the health service. “If it stops another child from having destroyed joints, then it’s got to be done, and I’m all for it,” she says.