Caitlin Ryan, 13, has systemic juvenile rheumatoid arthritis, a rare form of the joint-attacking disease. At first, her mom thought she hurt her knee.
"Within a three-week period, she went from being a real happy toddler to almost becoming immobile," said Colleen Ryan, Caitlin's mother. "When I saw her every day in so much pain, that she was literally taking Vicodin multiple times a day and still she would limp to school and stay the whole day."
"Instead of killing the entire immune system of the patient, you selectively go after that protein that causes the inflammation, the fevers, the rashes and so on," said Dr. Andreas Reiff.
It's risky, because the drug can have many serious side effects. For Caitlin, it worked.
"I feel a lot better. I'm getting back to where I can walk steady, I can run," said Caitlin. "I can actually run."
If you can do all you can to preserve a child's joints until adulthood, doctors say the symptoms start to disappear, but experts point out the lingering effects are more than just physical.
"Children who had arthritis and they grew up and became adults, they had tremendous difficulties with self-esteem, they had tremendous difficulties finding appropriate jobs," said Reiff.
Through working with the Arthritis Foundation, Caitlin understands how to deal with obstacles, and says she's even learned from having arthritis.
"I think it's actually going to make me stronger than I would have been without it," said Caitlin.
Possible side effects of Actemra include rash, muscle weakness and shortness of breath.