The ABCs of Food Allergies
Approximately 8% of children and 2% of adults suffer from true food allergies. When the culprit food is eaten, most allergic reactions will occur within minutes. Skin symptoms (itching, urticaria, angioedema) are the most common, and occur during most food reactions. Other symptoms can include nasal (sneezing, runny nose, itchy nose and eyes), gastrointestinal (nausea, vomiting, cramping, diarrhea), lung (shortness of breath, wheezing, coughing, chest tightness), and vascular (low blood pressure, light-headedness, rapid heart beat) symptoms. When severe, this reaction is called anaphylaxis, and can be life threatening.
Allergy or Intolerance?
Most reactions to food are probably not allergic in nature, but rather intolerance.
This means that there is no allergic antibody present against the food in the person. Intolerance can be classified as toxic and non-toxic. Toxic reactions would be expected to occur in most people if enough of the food was eaten, examples include alcohol, caffeine or in cases of food-poisoning. Non-toxic food intolerance occurs only in certain people, such as lactose intolerance, which is due to the deficiency of lactase, the enzyme which breaks down the sugar in milk and dairy foods. Patients with lactose intolerance experience bloating, cramping and diarrhea within minutes to hours after eating lactose-containing foods, but do not experience other symptoms of food allergies.
Non-allergic Immunologic Reactions