Disclaimer: Our daughter hasn't had head lice but is just starting into school so the chances are increasing.
Certain head lice shampoos and products shouldn't be used by those with JRA. Basically those with pesticides in them shouldn't be used by children with Autoimmune diseases. A link to a sad story is here: http://www.headlice.org/jesseproject/index.htm
Naproxen can cause children to bruise more easily. Our Rhuem isn't as concerned about the bruises on the front of the shins, but bruising on the arms or other locations should be looked at. We have noticed our daughter bruising more easily but it hasn't been too bad.
Omega 3's can also cause easier bruising.