Food Allergy or Intolerance?

About 1 in 20 Australians have a transient food allergy or intolerance. However,  food allergy and food intolerance are two separate things. So what basically is the difference between a food allergy and food intolerance?

Food Allergies are the abnormal reaction of the body’s immune system caused by a food that is normally harmless to most people.  Some foods act as allergens (the foreign particles); activating the body’s immune system to react against it and cause an abnormal reaction inside the body. The reactions can range from mild, like a skin rash, congestion or runny nose or it might be more severe and cause shortness of breath.  In Severe cases, it may cause anaphylaxis which causes difficulty breathing, swallowing, swelling of the lips, tongue and throat.  This can progress to loss of consciousness and if not treated urgently, it can lead to death.

Food intolerance, on the other hand is a non-allergic reaction to food. Though the body shows signs of discomfort and disease to certain foods, this is not immune related. The common cause of food intolerance is due to the absence of certain enzymes and chemicals, which help to digest a particular food.

There’s been a marked increase in food allergies and food intolerances in the westernized countries, which raises the concerns about the diet within these areas.

Australian Statistics:

Amongst the developed countries, Australia is one of the countries with highest prevalence of food allergies. Usually children suffer more from the food allergies. According to 2008 WHO statistics, one in every 20 children suffers from food allergies in Australia. According to Journal of Allergy and Clinical Immunology (2007; 120:878-84), there is 5 1/2-fold increase in the rate of Australian hospital admissions between 1994 and 2005 for food-related anaphylaxis in the under-fives.
Food allergies are specified to certain protein and certain foods in particular. Eggs, nuts (especially peanuts), milk, sesame seeds, gluten, seafood, grains, soy, some berries, tomato, cucumber, white potato and mustard are the commonly known foods that act as allergens. Yeast and certain food additives are also potential allergens. Milk, egg, peanut, tree nut (walnut, cashew, etc.), fish, shellfish, soy, and wheat are the main allergen foods that account almost 90% of all the food allergies. All these food allergies have common signs and symptoms, which definitely resembles that of a food intolerance.

Common Signs and Symptoms of Food Allergy:

• Itching in mouth and or skin
• Hives, rashes, eczema, redness and soreness of skin
• Swelling of fingers, lips, neck and tracheal passage
• Nausea, vomiting and diarrhea
• Abdominal cramps
• Wheezing and shortness of breath
• Anaphylaxis

Signs and symptoms of Food Intolerance:

• Nausea, vomiting, diarrhea
• Headaches
• Skin rashes
• Constipation and Irritable Bowel Syndrome
• Nasal congestion
• Respiratory and/or abdominal discomfort

Generally a food allergy is diagnosed by the signs and symptoms accompanied by complete medical and personal history. In some instances, the patient is well aware of the food that causes allergic reactions. In case of anaphylaxis, certain blood tests are also done to rule out other causes. Usually, the doctor identifies the allergic reaction. To rule out allergies, a few allergens are also injected by the doctors (in controlled amount), and the reaction to the specific allergen can confirm the presence of allergy, but this test is not common for food allergies. For the confirmation of allergy tests like skin scratch test, RAST and ELISA are also performed.

Primary treatment for food allergy is to avoid the trigger food. Once, the food is identified, it is comparatively easy to avoid. Other treatments involve the symptomatic treatment for the respiratory and gastrointestinal problems. In case of anaphylactic reaction, either self administered or clinically administered epinephrine is injected. Certain antihistamines and bronchodilators are usually administered to relieve the extremely disturbing signs and symptoms. Research is being done for the development of something similar to allergy shots, to overcome the food allergy issues.