Are allergies and hayfever hereditary?

Are allergies and hayfever hereditary?

If you suffer from allergies, you may wonder if you’ve inherited the condition from your parents, or if it is possible that you could be responsible for passing an allergy on to your children. The answer is unfortunately yes, in fact most allergies are inherited. When one parent has an allergy, the child has a 50% risk of also having one. When both parents are allergic, this risk increases to 75%. However, although parents may pass on the tendency to be allergic, children may not inherit an allergy to the exact same allergen.1

However, the reasons why a person develops an allergy are not completely understood. Several factors, other than the heredity risk factor, are thought to be involved. This means that although a family history of allergies in a parent or sibling is a significant risk factor, there are other environmental factors that are also implicated.

Some risk factors can be modified and doing so may help to minimise the risk of your child developing allergies. Risk factors that may cause allergies to develop include:

  • Dietary factors, such as introducing your baby to cow’s milk, soy milk formula or solid foods before three to four months of age.
  • Having a spring birth month. Babies born during this time of the year have a higher risk of developing seasonal allergic rhinitis, or hayfever.
  • Passive exposure to cigarette smoke also increases a child’s risk of developing allergic respiratory symptoms.2

As a parent, there are things you can do to minimise the risk of your baby developing allergies.

These include avoiding smoking when pregnant and not smoking in the presence of the child once they are born. Breastfeeding has been shown to decrease the risk of allergies in early childhood and where possible, babies should be breastfed for at least six months. However, even with these steps in place, a high risk child may still develop allergies, including hayfever.2