You know to tell the dentist not to use epinephrine, I hope. It's a big trigger for many people. (As I understand it, it's added to Xylocaine because the epi reduces bleeding, so the actual anesthetic to avoid is Xylocaine+epinephrine.) This is from a post somewhere else: "Anesthetics containing epinephrine (such as Xylocaine) and nitrous oxide have been identified by some people as triggers. Ask your dentist to use something else: Prilocaine seems not to cause bad effects. Another person has mentioned carbocaine as an anesthetic that didn't trigger his CH."