Food Allergies & Severe Reactions

Food Allergies are sensitivities caused by a reaction of the body’s immune system to specific proteins in a food. Food allergy symptoms occur when the immune system decides that a protein in a food is harmful, and begins an attack when that food enters the body. The most common food allergies are peanuts, tree nuts (such as almonds and walnuts), sesame seeds, milk, eggs, seafood (fish, crustaceans and shellfish), soy, wheat and sulphites (a food additive). The Canadian Food Inspection Agency is working with the food industry to ensure that the common food allergies are always declared in the ingredient list on the food label, and that they develop allergen prevention strategies to manage the allergy risk.

The most common symptoms of a food allergy are:

• Skin problems including hives; tissue swelling, especially of the face and around the mouth; itching and reddening of the skin; and eczema in young children.
• Breathing problems; stuffy, runny nose and itchy eyes; worsening of asthma in asthmatics.
• Digestion problems; nausea, vomiting, diarrhea
• The most severe allergic response is anaphylaxis, which may involve all of the above symptoms and can be life threatening.

How are food allergies and severe allergic reactions treated?

The prevalence of true food allergy is far less than generally perceived by the public. Although one out of 4 adults believes to have suffered from allergic reactions after ingestion or handling of food, it is estimated that 1-2% of the adult population and 4-6% of the paediatric population suffer from allergic reaction to food. Prevalence of allergy is highest in infancy and early childhood, and diminishes with increasing age. Infants often outgrow their allergy to cow’s milk and eggs; symptoms can diminish or disappear by age 5-7. Many food allergies, e.g. to nuts, peanuts, fish and crustacea, tend to remain a problem for a lifetime.

BIOLOGICAL MECHANISM AND SYMPTOMS

Currently there is no cure for food allergies. The only option is complete avoidance of the specific allergen. Appropriate emergency treatment for anaphylaxis includes an injection of adrenaline. Adrenaline must be administered as soon as symptoms of a severe allergic reaction appear. Food Intolerance is a food sensitivity that does not involve the individual’s immune system. Many food intolerances are caused by inadequate digestion, absorption, and/or processing of the food when it is eaten. As a result, unwanted food materials may build up, and have a harmful effect. Symptoms of food intolerance depend on the amount of the offending food eaten – the more you eat, the worse the symptoms tend to be. Symptoms of food intolerance vary and can be mistaken for those of a food allergy. Food intolerances are more likely to originate in the gastrointestinal system. Lactose intolerance is an example of a food intolerance, which occurs in people who lack an enzyme called lactase. Lactase is needed to digest lactose (a sugar in milk). Symptoms of lactose intolerance may include abdominal pain and bloating, diarrhea and flatulence. Ref: Canadian Food Inspection Agency, Health Canada and Dietitians of Canada websites, 2007