There are many in Maryland. Go to TurntheCorner.org and request a doctor list through email. They will get back to you in short order.
[email protected] is the email address -- just found it.
Also, I cannot track this guy down but he is in Maryland and he's excellent
http://www.lymemd.blogspot.com/
Get in to see him and you are in excellent hands. The guy is the HOUSE of the Lyme world. ( He has it himself.)
Make sure you have GOOD RAPPORT -- with not just doctor but staff. Things can happen during treatment that require interaction with staff members and if they suck, you suffer.
Voice of experience. Good luck to your aunt and fam. May you put this nightmare behind you soon!