Food allergies occur when the immune system identifies the proteins in a particular food as harmful to the body, subsequently reacting to try to "fight off" the "harmful" proteins (which are in fact harmless). Citrus allergy is a fairly common food allergy. It is more common in adults than in children.

Citrus fruits include oranges, lemons, limes and grapefruits.

Some symptoms of a citrus allergy include:

  • Itching or swelling of the mouth, tongue or lips
  • Skin reactions (eczema, hives, swelling and redness of the extremities or face)
  • Gastrointestinal symptoms (abdominal pain, nausea, vomiting, diarrhea)
  • Respiratory symptoms (runny or stuffy nose, coughing, sneezing, wheezing, difficulty breathing)
  • Cardiovascular symptoms (drop in blood pressure, lightheadedness, fainting)

If you experience symptoms of anaphylaxis, which include nausea, vomiting, weak or rapid pulse, difficulty breathing, confusion and loss of consciousness, seek immediate medical attention, as this can be fatal.

Citrus allergy symptoms may occur from consuming a tiny amount of citrus fruit or fruit juice, or just from touching the peel or breathing in airborne particles of the fruit. Symptoms may appear immediately or several hours after coming into contact citrus fruit.

If you have any of the above-listed symptoms after consuming or coming into contact with citrus fruits, you should see an allergist to find out exactly which fruits you are allergic to. Testing methods include a skin prick test, in which the doctor places a small amount of the suspected allergen onto a scratch on your arm or back; an Immunoglobulin E (IgE) blood test; or a supervised "food challenge."