Symptoms of food allergy appear immediately or within a few hours of eating. The primary symptoms of food allergies are wheezing, hives, and a hoarse voice. You may experience difficulty swallowing, difficulty breathing, nausea, vomiting, diarrhea, abdominal pain, itching, light-headedness, fainting, nasal congestion, and runny nose. Your eyelids, tongue, and lips may swell. Your throat, tongue, mouth, or skin may itch.
A potentially life threatening reaction, anaphylaxis, requires immediate medical treatment. Symptoms of anaphylaxis include hives, itching and pale or flushed (reddened) skin. It can be difficult to breathe if the airways narrow and the throat and tongue swell. A wheezing noise may be heard while breathing. The pulse may feel weak and fast. Nausea, vomiting, diarrhea, dizziness, and fainting can also occur.
A severe anaphylaxis reaction can cause a person to develop anaphylactic shock and stop breathing or stop the heart. Symptoms of anaphylactic shock include a sudden drop in blood pressure, difficulty breathing, and a loss of consciousness. Again, immediate emergency medical treatment is needed. In some cases death can result.