One of the most common food allergies is a sensitivity to peanuts, a member of the bean family. Peanut allergies may be severe, but children with peanut allergies sometimes outgrow them. Tree nuts, including pecans, pistachios, pine nuts, and walnuts, are also common allergens. Sufferers may be sensitive to one particular tree nut or to many different tree nuts. Also seeds, including sesame seeds and poppy seeds, contain oils where protein is present, which may elicit an allergic reaction.

Egg allergies affect about one in fifty children but are frequently outgrown by children when they reach age five. Typically the sensitivity is to proteins in the white, rather than the yolk.

Milk, from cows, goats or sheep, is another common food allergen, and many sufferers are also unable to tolerate dairy products such as cheese. A very small portion of children with a milk allergy, roughly ten percent, will have a reaction to beef. Beef contains a small amount of protein that is present in cow’s milk.

Other foods containing allergenic proteins include soy, wheat, fish, shellfish, fruits, vegetables, spices, synthetic and natural colors, and chemical additives.

Although sensitivity levels vary by country, the most common food allergies are allergies to milk, eggs, peanuts, tree nuts, seafood, shellfish, soy and wheat. These are often referred to as “the big eight.” Allergies to seeds — especially sesame — seem to be increasing in many countries. An example of allergies more common to a particular region is the surplus rice allergies in East Asia where rice forms a large part of the diet.

Cross reactivity

Some children who are allergic to cow’s milk protein also show a cross sensitivity to soy-based products. There are infant formulas in which the milk and soy proteins are degraded so when taken by an infant, their immune system does not recognize the allergen and they can safely consume the product. Hypoallergenic infant formulas can be based on hydrolyzed proteins, which are proteins partially predigested in a less antigenic form. Other formulas, based on free amino acids, are the least antigenic and provide complete nutrition support in severe forms of milk allergy.

People with latex allergy often also develop allergies to bananas, kiwi, avocados, and some other foods

Food allergy testing