Food allergies are not as common as you might think. Food intolerances are more common, but they are not the same as allergies.

It’s hard to get accurate figures on food allergies. This is partly because people often claim to have allergies even though tests show they don’t.
We hear a lot in the media about food allergies. In fact, food allergies are uncommon. And the good news is that most children who have allergies grow out of them.
What is a food allergy?
When you are allergic to a food substance, your immune system reacts to that substance as though the substance is toxic. Your immune system tries to protect your body by releasing chemicals (such as histamines) into the body’s tissues. The resulting effect on the body can be quite major, even with tiny amounts of food.
What is a food intolerance?
A food intolerance is a reaction to a substance in the food you’re eating. Unlike allergies, intolerances are not caused by your immune system reacting to the food.
Intolerance reactions are generally less severe than allergic reactions. They can still cause a lot of discomfort, though. Some people can cope with small amounts of foods they’re intolerant of, and they generally have fewer symptoms than people with allergies.
About 90% of food allergies are caused by seven foods:
The remaining 10% of allergies are caused by a wide variety of other foods.
The most common food intolerances are caused by:
Allergies
Most children grow out of their food allergies by adolescence, especially children who are allergic to milk, egg, soybean or wheat.
Allergies to peanuts, tree nuts, fish and shellfish are more likely to be lifelong.
Giving a child even a small amount of a food she’s still allergic to can cause a severe or life-threatening reaction. It’s best to do this under appropriate guidance from your doctor or allergist.
Intolerances
Whether a food intolerance is a temporary or lifelong problem depends on the particular food and the reason your child’s body is reacting to it. It’s best to speak to your health professional about whether your child’s food intolerance can be treated.
Allen, K. J., Hill, D. J., & Heine, R. G. (2006). Food allergy in childhood. Medical Journal of Australia, 185, 394-400.
American Academy of Pediatrics. Retrieved 23 November, 2007, from http://www.aap.org/sections/allergy/child.cfm.
Arshad, S. H. (2005). Primary prevention of asthma and allergy. Current Reviews of Allergy and Clinical Immunology, 116, 3-14.
Australasian Society of Clinical Immunology and Allergy. Food Allergy. Retrieved 4 August, 2009, from http://www.allergy.org.au/content/view/167/140/.
Better Health Channel. Food allergy and intolerance. Retrieved 23 November, 2007, from http://www.betterhealth.vic.gov.au/BHCV2/bhcarticles.nsf/page/Food_allergy_and_intolerance?OpenDocument.
Greer, F. R., Sicherer, S. H., & Burks, A. W. (2008). Effects of early nutritional interventions on the development of atopic disease in infants and children: The role of maternal dietary restriction, breastfeeding, timing of introduction of complementary foods, and hydrolysed formulas. Nutrition and Section on Allergy and Immunology. Pediatrics, 121, 183-191.
Kagan, R. S. (2003). Food allergy: An overview. Environmental Health Perspectives, 111, 223-225.
Keepkidshealthy.com. Food Allergies. Updated 2006. Retrieved 23 November, 2007, from http://www.keepkidshealthy.com/welcome/commonproblems/food_allergies.html
Nowwak-Wegrzyn, A. (2003). Future Approaches to Food Allergy. Pediatrics, 111, 1672-1680.
Ortolani, C., & Pastorello, E. A. (2006). Food allergies and food intolerances. Best Practice Research Clinical Gastroenterology, 20, 467-483.
Prescott, S. L., & Tang, M. L. (2005). The Australasian Society of Clinical Immunology and Allergy position statement: Summary of allergy prevention in children. Medical Journal of Australia, 182, 464-467.
Rona, R. J., Keil, T., Summers, C., Gislason, D., Zuidmeer, L., Sodergren, E., Sigurdardottir, S. T., Lindner, T., Goldhahn, K., Dahlstrom, J., McBride, D., Madsen, C. (2007). The prevalence of food allergy: A meta-analysis. Journal of Allergy and Clinicial Immunology, 120, 638-646.
Sampson, H. A. (2004). Update on food allergy. Journal of Allergy and Clinical Immunology, 113, 805-819.
Sicherer, S. H. & Sampson, H. A. (2007). Peanut allergy: Emerging concepts and approaches for an apparent epidemic. Current Reviews of Allergy and Clinical Immunology, 120, 491-503.