The allergist here in Maine said he was not allergic to lidocaine, however he probably reacted because of the enormous dose he had been given. That was the first time he reacted to it.
I know it's not the same procedure, but I work for Radiology where they use lidocaine a lot and many many people have reactions. There are alternatives. Seems to me they should explore them rather than risk an overnight stay every time he has something done.