“My child has arthritis? Isn’t that an old person’s disease?”
Many people do not think that arthritis can occur in children and so many children experience pain for months or years before the diagnosis of arthritis is made and treatment begun. Children with arthritis frequently experience difficulty because it is not understood that children can develop arthritis and if untreated can damage joints, and soon children as young as 8 years may need joint replacement.
Is it common?
Arthritis affects approximately one child in every 1,000 in a given year. Many children may have what is called an acute inflammatory arthritis following a viral or bacterial infection usually after an upper respiratory tract infection or tummy bug. This arthritis is often painful but usually lasts for a short period and wanes within a few weeks or months as the infection resolves. Other causes of joint pain in children include the common growing pains, diseases of the bone marrow like leukemia, and sickle cell disease.
Juvenile idiopathic arthritis (JIA) is however the most common type of arthritis in children affecting 1 in every 250 children and is a chronic form of arthritis. JIA is also called juvenile arthritis or juvenile rheumatoid arthritis.
What are the signs and symptoms and how is it diagnosed?
There are three main forms of juvenile idiopathic arthritis (JIA), which are classified by how they start. These forms are pauciarticular (less than four joints affected), polyarticular (four or more joints affected), and systemic-onset (inflamed joints with high fever and rash). Diagnosis is difficult and often delayed in children as doctors and parents may be misled because most children, especially toddlers and preschoolers do not complain of pain. Swellings may be attributed to sprains and therefore overlooked. Most of the time, the complaint of pain is attributed to the common growing pains. Hence by the time they are diagnosed, significant damage may have been done to the joints. Limping and stiffness may be noticed and the child limps or appears clumsier, especially in the morning or after a nap. Joint swelling is common, often first noticed in larger joints like the knee.
Many children with the pauciarticular type of juvenile idiopathic arthritis (JIA) develop inflammation of the eye (iridocyclitis). The inflammation is usually painless and so can go undetected and may lead to scarring of the lens of the eye and permanent visual damage or even blindness, if not treated early. Diagnosis can be difficult because joint pain can be caused by many different types of problems. No single test can confirm a diagnosis, and blood tests can be entirely normal in many children.
Some of the most common blood tests for suspected cases of juvenile idiopathic arthritis include:
• Erythrocyte sedimentation rate (ESR) and C-reactive protein. An elevated rate can indicate inflammation.
• Blood counts. To rule out infections and leukemia
• Anti-nuclear antibody. These are proteins commonly produced by the immune systems of people with certain autoimmune diseases. In children it may be a pointer to eye disease.
• Rheumatoid factor and Cyclic citrullinated peptide (CCP). These antibodies are commonly found in the blood of adults who have rheumatoid arthritis.
X-rays may be taken to exclude other conditions, such as:
• Congenital defects
Typically, this involves medications that reduce inflammation, that is, non-steroidal anti-inflammatory drugs (NSAIDs). Nonsteroidal ant-inflammatory drugs are enough for many children with polyarticular juvenile rheumatoid arthritis, but more severe cases may require more aggressive “second-line” medications, such as sulfasalazine, or methotrexate. Severe cases requiring steroids or second-line medications should be taken under the care of experienced physicians. Taking too many steroids for a long period causes lots of problems, like short stature and weak bones in children and care must be taken to wean them off as early as symptoms would allow.
A newer form of medication, biologics called TNF-blockers, is now being used. Tumor necrosis factor alpha (TNF-alpha) is a substance made by cells of the body that has an important role in inducing inflammation. By blocking the action of TNF-alpha, TNF-blockers reduce the signs and symptoms of inflammation and can result in a rapid and considerable decrease in disease activity and better quality of life.
Because the eye disease (uveitis) is more common in children with a positive test for antinuclear antibodies (ANA), these children require eye examinations every three months by an eye specialist. All other children with JIA need eye examinations every six months.
Pauciarticular JIA may cause the bones in the legs to grow at different rates. When a joint is inflamed by the arthritis, its blood supply increases and so it grows faster and larger, with the result that one leg is longer than the other. This results in the child walking with a limp and this damage the knee and the hip leading to premature or degenerative arthritis, from ‘wearing out’ of the joints by the time the child is an adult.
If not recognized early this can result in significant leg-length discrepancy. To correct this, a lift is placed in the shoe on the short side to correct the effect of the different leg lengths. This allows the child to walk more normally and reducing excess pressure on the hip. The next step is to monitor growth. When the child is getting closer to fully grown, an orthopedist can look at x-rays of the legs and try to guess when the bones are going to stop growing. If the leg with arthritis is 3 cm longer than the other leg, they will look at the x-rays and try to guess when there is 3 cm of leg growth left and stop the growth on the leg that is too long and allow the short leg to catch up. This can be done with a very simple operation.
Treatment of children with inflammatory arthritis is challenging as you in effect have to treat 3 people; the child and the parents. Parents would rightly be wary about treating their children with immunosuppressive medications and may refuse treatments which they would have willingly taken themselves for adult arthritis. Steroids which used to be the mainstay of treatment can have serious side effects on growth and bone health.
Most children are fear needles and monitoring them on treatment can be demanding. The needs of the child especially developmental needs like ensuring that school and social activities are maintained have to be factored in the care plan. Children especially when they transit into adolescence can find it difficult as their priorities and developmental needs change and you must ensure that they can fit in their social and work needs. Non compliance with medications is a usual problem and must be dealt with tactfully.
Childhood arthritis persists into adulthood in about 50% of patients and the chronic inflammation may later lead to increase risk of atherosclerosis (cholesterol deposits in blood vessels causing blockage) and heart disease.
A multidisciplinary approach to management including physical and occupational therapists and orthopedic surgeons is needed for the best outcomes.