Juvenile arthritis is the chronic inflammation of one or more joints that develops in a person younger than 16. About 285,000 children in the United States have juvenile arthritis.
Children with juvenile arthritis may be frequently absent from school, less able to participate in activities or have more limited career options. The child's parents and siblings may also be affected by the psychological and financial stress of chronic illness in a family member.
The disease can follow these patterns:
- Systemic onset, which starts with very high fevers, frequently a skin rash and shows inflammation in many internal organs and the joints. About 10% of children with arthritis have this type.
- Pauciarticular onset, which affects fewer than five joints. About 50% of all children with arthritis have this type. Some are young (infants to age 5) and have a risk of developing inflammatory eye problems, making regular eye exams essential. Others are older and may evolve into one of the adult forms of arthritis.
- Polyarticular disease, which affects five or more joints, and can begin at any age. Some of these children have adult type rheumatoid arthritis that begins at an earlier age than usual.
The different patterns of juvenile arthritis may require different treatment approaches and have different outcomes. Regardless of what pattern of juvenile arthritis develops, an affected person will have painful, inflamed joints. This may result in stiffness (particularly in the morning), limping and reluctance to engage in certain activities.
Causes and Risk Factors
The cause of juvenile arthritis is not known. There are some indications that certain types of childhood arthritis or children who develop particular complications from the condition have genetic origins. Although some genetic markers may be associated with an increased chance of developing arthritis, these conditions are not regarded as hereditary and rarely affect more than one family member. Some evidence suggests that there could be infectious triggers in a genetically predisposed child.
Juvenile arthritis may be difficult to diagnose because often children compensate well for loss of function and may not complain of pain. Observations of limping, stiffness when awakening, reluctance to use a limb or reduced activity level may be clues.
Tests commonly positive in adult arthritis (rheumatoid factor in the blood or changes on X-rays) are usually negative in childhood types. A number of other conditions can mimic juvenile arthritis, such as infections, childhood malignancies, conditions of the muscles and bones or other less common rheumatic disease. Further evaluation to exclude these may be needed before a diagnosis is confirmed.
The choices of drugs for children are similar to those for adult arthritis and include:
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, and slower acting agents, such as methotrexate, sulfasalazine and hydroxychloroquine, for more severe cases. The doses must be adjusted for the size of the child. Preference may be given to liquid preparations or less frequently dosed medications to help with compliance.
- Steroids (such as cortisone), which must be used with caution because they can affect the child's growth or cause other side effects. Some drugs for adults are not FDA-approved for use in children.
- Physical and occupational therapy can prevent disability
- Splints, a regular home exercise program or outpatient treatment are often effective
Children should participate in regular school activities, extracurricular activities and family responsibilities as much as possible.