Cross-reactivity in allergic reactions occurs when the proteins in one allergen (typically pollen) are similar to the proteins found in another allergen (typically a food). For example, if your child is allergic to birch tree pollen, he/she may also find that eating apples can cause an allergic reaction.
Cross-reactivity doesn’t only occur in tree pollen and fruit, but it can occur in many other allergens. In the overview below you can look up where your child is allergic to, this is stated in the left column. The center column indicates which products are strongly similar in terms of protein structure. Finally, you will find in the right column a number which is indicating the risk (in percentage) that a cross reactive reaction will occur and will cause your child allergic symptoms.
An example….. Your son is allergic to cow’s milk, the chance he will react to goat’s milk is then 92%. The chance your son will get an allergic reaction to mare’s milk is much lower, that is 4%.
Most people who are allergic have little to no burden of cross reactivity. It is therefore not necessary to abstain your child from certain foods as a precaution. If you suspect that your child is showing cross reactive reactions to certain foods, then you should discuss this with your child’s attending physician.