You should go to the doctor and have a complete allergy blood test done. I just had to do this with my daughter after she had that reaction to fish. It progressively got worse to her vomiting after eating it before I realized it was the fish probably causing it. Keep Benadryl on hand. Common things for allergies are fish, shellfish, wheat, gluten, peanuts, milk. I'm not a doctor but I've just went through this. Really evaluate what you ate when it happened. Each reaction will get worse and could cause your throat to swell and block breathing. Hope this helps.