According to a researcher, due to the higher risk of developing arthritis, children suffering from Down’s syndrome should have a musculoskeletal examination annually.
Despite the fact that there aren’t any researches regarding the incidence of Down’s arthropathy, early speculations show that arthritis in Down syndrome patients might be more common than juvenile idiopathic arthritis. Charlene Foley, MBBS at Our Lady’s Children’s Hospital in Dublin considers the prevalence to be at 8.7/1000 compared to 1/1000.
Foley stated at the annual meeting of British Society of Rheumatology that although arthritis in Down’s syndrome patients is more common the diagnosis is more than often delayed. Because the diagnosis is constantly delayed the treatment is also postponed and patients tend to suffer from more joint damage and disability at the time of the diagnosis.
The first association of arthritis with Down’s syndrome has been reported about 30 years ago. Despite this, the largest case series was of only nine children.
Foley and her colleagues conducted musculoskeletal examinations on 503 children with trisomy 21. They managed to identify 33 children with arthritis. When taking into consideration the other cases they have at their clinic, they managed to estimate a prevalence of 18 to 21/1000 which is much higher than the initial estimation.
They’ve also made a comparison between the Down’s syndrome group and another group of 33 juvenile idiopathic arthritis patients and noticed that those who suffered from Down’s syndrome had higher numbers of restricted joints suggesting the fact that Down’s arthropathy might be a more aggressive disease. The Down’s arthropathy group also experienced radiographic changes such as osteopenia, joint space narrowing and subluxations.
Foley stated that only 11% of the parents suspected that their children had arthritis, suggesting the fact that people are not aware of the higher risk of arthritis in children with Down’s syndrome. This lack of awareness seems to be present among healthcare professionals as well, 65% of them not being aware of the risks of arthritis.
There are various other issues that may prove problematic when diagnosing Down’s syndrome children with arthritis, such as their ability to speak and their locomotive skills. They can have hypermobile joints which can cause difficulties in accurately diagnosing arthritis.
The treatment can prove difficult. Studies have shown that 75% of the children treated with methotrexate had suffered from nausea and had to stop taking the drug. Methotrexate can also cause gastrointestinal toxicity to children with Down’s syndrome.
Foley said that the normal treatment so far involves low doses of methotrexate and administer ondansetron to all children. More research is needed to better understand Down’s arthropathy and to find the best method of treatment.