Hi, It seems to be due to food allergy as you had a same episode earlier . Food allergy can be diagnosed only on the basis of detailed history taking and thoroughly clinical examination by an expert. Although there are laboratory allergic testing of food is being done nowadays but none of them is reliable clinically and also adds extra cost to the patient. The best way to cure allergy is to avoid contact of that particular allergen. However there are very good medicines like epinephrine,steroids, antihistamines, mast cell stabilizers are available in market to combat allergic symptoms. You can take anti emetics (ondansetron 4mg) with the advise from your doctor. consult your physician if there is continuous vomiting.