Any doctor in the US should be able to sign it if yours won't, Nicole. If your PCP won't sign it, you can at least ask the Infectious Disease doctor, but to be honest, most ID doctors don't understand Lyme. That's why the "LLMDs" are a separate group.
Nicole, not IDSA, ILADS,
http://ilads.org/ilads_media/physician-referral/
Try that.