The difference between a food allergy and an intolerance

While both food allergies and food intolerances are unpleasant to the person affected, they are very different. If you've had a reaction to certain foods, it's important to know if what you've experienced is an allergy or an intolerance.

• A food allergy is when the body's immune system reacts to the presence of a food allergen by producing an immune response.
• This reaction is usually immediate: often within minutes, but certainly within the hour.
• Allergies are severe, consistent and can be caused by even a tiny amount of the allergen.
• An allergic reaction will happen every single time, without fail, and be the same each time.
• They often affect the respiratory system or the skin, resulting in anaphylaxis or hives.
• An allergic reaction is serious, and can even be fatal. Approximately 90 per cent of all allergic reactions are caused by allergies to peanuts, tree nuts, eggs, milk, soy, wheat, fish or shell fish.

• A food intolerance is when the body lacks the enzymes required to metabolize a particular food.
• Reactions are often digestive, such as bowel problems or nausea, and may involve the skin, such as skin rashes.
• Reactions are gradual rather than immediate, and may vary based upon the amount of food ingested or the frequency with which it's ingested.
• Food intolerances are non-life threatening.

Examples of food intolerances are lactose intolerance and celiac disease, in which the body cannot metabolize gluten.

An allergic reaction is severe and can even be fatal. The allergy needs to be confirmed by a specialist, and other related allergies need to be ruled out. The allergic person may need to carry a medication to use in the event of a reaction, as anaphylactic shock can set in within minutes and needs to be treated immediately. The allergen or allergens identified need to be avoided at all costs.

In the case of a food intolerance, appropriate management is important for quality of life. In some cases, all traces of certain foods may need to be avoided, while in other cases, small quantities may be tolerated with no ill effects at all.

If you suspect you have a food allergy or intolerance, see your doctor to discuss your path to an accurate diagnosis.