Food-allergy symptoms include hives or itching, wheezing or breathing difficulties, dizziness, abdominal distress, mouth swelling or tingling, and swelling, particularly in the face, states Mayo Clinic. Severe food allergies can cause anaphylaxis, with symptoms including swelling of the airways or throat, increased pulse, dizziness, loss of consciousness and shock.
Food allergy symptoms often surface within a few minutes of eating the trigger food, according to the American College of Allergy, Asthma and Immunology. Most allergic reactions happen within two hours but can take four to six hours to appear. The reaction to a certain food isn't always the same. A more severe reaction is possible even if the first incident only caused mild symptoms.
Anaphylaxis is a life-threatening allergic reaction, notes Food Allergy Research & Education. In addition to breathing problems, the condition causes a sudden drop in blood pressure.