Behind the Pain

Understanding on juvenile rheumatoid arthritis.

As a practicing pediatric rheumatologist, I am often surprised by how few people are aware that children get arthritis. They do! What’s this like? Imagine how difficult it must be for a child to suffer pain, swelling and stiffness of the joints. Imagine a toddler who reverts to crawling because walking hurts, or a 4 year old who has to be carried for an hour every morning. Imagine a teenager who needs to take long baths or sit in a heated car every morning to loosen up enough to comfortably attend school. Now imagine that one of these children is incessantly told he or she has growing pains— and the family’s frustration while awaiting a proper diagnosis and appropriate treatment.

Juvenile rheumatoid arthritis (JRA), which is also known as juvenile idiopathic arthritis (JIA), is one of the most common childhood rheumatic diseases. JRA is a significant cause of disability in children. But it may go unrecognized until tremendous joint impairment brings affected children to medical attention. In the case of JRA, disability from the long-standing disease may include issues such as persistent pain and functional impairment, leg length discrepancy, micrognathia— a condition where the lower jaw and chin become smaller— and visual damage. School absences and the psychosocial impact of chronic pain are also a major concern.

Children with JRA often respond well to treatment. However, the shortage of trained pediatric rheumatologists is a disservice to children with the disorder. In parts of the United States, access to pediatric rheumatology is limited, and children are managed by pediatricians or adult rheumatologists. In addition to rheumatologists, JRA patients need access to ophthalmologists experienced in the care of children as JRA may be complicated by vision-threatening inflammatory eye disease (uveitis, iritis), which must be rigorously screened. Physical and occupational therapists and alternate pediatric sub-specialists are integral to the kind of multidisciplinary care children with JRA require.

About 300,000 children in the United States suffer from some form of juvenile arthritis. JRA is merely one category of juvenile arthritis. And it comprises several diseases characterized by arthritis of the peripheral joints. The three main subtypes of JRA are pauciarticular (or oligoarticular), polyarticular and systemic onset.

The number of joints involved at six months of disease duration determines a child’s type of JRA. In all subtypes, arthritic symptoms may include pain, swelling and stiffness of affected joints. Symptoms are typically worse with accompanying stiffness after long periods of immobility, such as when awakening in the morning, sitting in school or traveling for long distances in an automobile. Parents may note that children with JRA walk with an abnormal gait in the mornings or want to be held and carried for a period of time until they loosen up.

With pauciarticular disease, in which fewer than five joints are affected at six months, large joints like the knees and less commonly the ankles are affected. Hip involvement is not seen in pauciarticular JRA. Involvement of small joints should raise the suspicion on the part of a treating physician for an alternate diagnosis. Polyarticular JRA, in which five or more joints are affected at six months of disease duration, tends to involve smaller joints, although larger joints including the hips may be involved as well.

Systemic onset JRA is unlike the other subtypes in that children have daily fevers and rashes that may precede joint involvement. Kids may have enlargement of the liver, spleen and lymph nodes, and other signs of systemic disease. Blood work in these children shows abnormally elevated inflammatory markers. And children with systemic onset JRA tend to follow a more aggressive disease course requiring the use of corticosteroids and other immunosuppressive medications.

No single cause of JRA has been identified. But with evolving research into the function of the immune system, a number of potential pathogenic mechanisms have been described. The role of cytokines, inflammatory molecules in the circulation, has received considerable attention in recent years.

Certain medications are currently approved for the treatment of JRA, and several medications approved for use in adult arthritis are used off-label for treating children with arthritis. Children with JRA were previously subject to long-term disability often requiring joint replacement, splinting and inpatient rehabilitation. With the advent of biologic therapies, this is no longer always the case. Many practitioners begin with the use of nonsteroidal anti-inflammatories and, if necessary, may rapidly advance children to disease modifying anti-rheumatic drugs or biologic agents in an attempt to control the disease. Three biologic agents are currently approved for use in childhood.

To date, the use of biologic agents in childhood appears to be safe, and the FDA’s safety review is ongoing. However, as these medications are immunosuppressive, children taking these agents are at an increased risk for infection, particularly for tuberculosis. Lymphoma remains a concern and has been reported in children on these medications. Yet, at this point, malignancy does not appear to represent a significant risk in such patients. Certainly, these medications require supervised administration, monitoring of laboratory work and screening for infection and malignancy. This is best carried out by pediatric rheumatologists comfortable with the use and management of these medications while balancing the potential side effects in children.

Early identification and treatment of children with JRA has been shown to decrease the risk of long-term disability and disease progression. As the community at large becomes increasingly aware of the existence of arthritis in childhood, children may be appropriately referred and treated in a timely fashion for the best possible outcome.