you could try talking it over with your gp and ask for a referal to a dietician. how severe were his allergy reactions?? you may need further tests to rule them in or out or if the reaction bad then the cause in obvious. Doctors and allergies are a nightmare. Both my kids had food allergies, my son out grew his egg allergy but has a nut allergy and my daughter has just out grown her dairy allergy so we are having a fun summer of ice cream after years of stress. Food allergies are hard work and people don’t understand.