Is this the show with the episode about...

(NOTE: The episode I'm looking for may have been on a different show; I know I watched two or three different medical shows that were all very similar and I can't remember which one this was on)

Does anyone know the name of the episode that was about a girl who had crippling pains in her joints?

I remember that her fingers would twist up and get stuck that way for days... the doctors couldn't figure out what was wrong with her and assumed it was an act or something (they might have blamed it on separation anxiety? I can't remember exactly...). Her mom sent her on a trip to another country to disprove this theory, where she ended up meeting someone who had Lyme Disease and described the symptoms to her, which happened to be the exact symptoms she was experiencing. Convinced she had Lyme Disease, she had the doctors test her for it again even though previous tests for Lyme Disease had come back negative. The tests came back positive this time, and the doctors realized that the previous tests had come back negative because they had given her something (pain medication? antibiotics? once again, I don't remember exactly, but it was something) that had destroyed whatever indicator would have caused the tests to come back positive.

Which episode was this? Or was it on a different show entirely? Does anyone know?

Also, if you do know which episode this was and my description was off, please feel free to correct me. =)