Yes. There is a disease called juvenile idiopathic arthritis. However, it is also possible that your child has a repetitive stress injury from overuse of a joint or limb. Have your child checked by an orthopedist.
Your son very well could have arthritis. Children do have it, most of the time it is in their legs. Finding a doctor that will dignose it is probably going to be the hard part. I would start at your child's or family doctor. But it is possible for them to have it.
