For some people, an allergic reaction to a particular food may be uncomfortable but not severe. For other people, an allergic food reaction can be frightening and even life-threatening. Food allergy symptoms usually develop within a few minutes to 2 hours after eating the offending food. Rarely, symptoms may be delayed for several hours. The most common food allergy signs and symptoms include: 
Tingling or itching in the mouth
Hives, itching or eczema
Swelling of the lips, face, tongue and throat or other parts of the body
Wheezing, nasal congestion or trouble breathing
Abdominal pain, diarrhea, nausea or vomiting
Dizziness, lightheadedness or fainting
 Anaphylaxis In some people, a food allergy can trigger a severe allergic reaction called anaphylaxis. This can cause life-threatening signs and symptoms, including: 
Constriction and tightening of the airways
A swollen throat or the sensation of a lump in your throat that makes it difficult to breathe
Shock with a severe drop in blood pressure
Rapid pulse
Dizziness, lightheadedness or loss of consciousness
 Emergency treatment is critical for anaphylaxis. Untreated, anaphylaxis can cause a coma or even death.