Allergists tend to prefer SPT for initial testing because, for most people, it's more sensitive. For us, even with ds2's severe scalp-to-ankle eczema, the results were accurate and matched both his reactions and the later RAST results. But, at 6 months old, he was only exposed via breastmilk and hadn't yet had an anaphylactic reaction. As I'm sure you've read, SPT requires that a small amount of the actual allergen be scratched onto the skin. It is not recommended for foods that have caused a previous ana reaction, so I think you are right to be concerned. In fact, the appropriate sequence in determining that a child has outgrown a severe allergy is 1. neg RAST, 2. neg SPT and, 3. in-office challenge--because the SPT is an actual exposure. It has been known to cause anaphylaxis.
Our allergist is great--he doesn't challenge our decision not to vax, he encourages EBF, and, when I requested RAST for ds2's last test, he had no problem with it at all. But, circlemama is right. You don't need an allergist to order a RAST; any dr. can do it. An unsupportive, uninformed allergist is worse than no allergist. If your ped. is supportive, ask them to order it. You already have an epi, so that fight is over.