15 month old with cutaneous MS

My 15 month old has cutaneous mastocytosis since birth. He has always had flushing and “splotchy” skin. On occasion I thought he had a hive. Today he had a hive and vomiting after eating strawberries. He has eaten other high histamine foods like tomato sauce, banana, and avocados. After our ER visit we were discharged with Benadryl and an Epi Pen. I’m asking to see pediatrician Monday. What do I need to ask for referrals to?