Allergies can develop at any point in life. The main causes for allergies are exposure to chemicals, heredity, and hygiene hypothesis. Heredity is a common cause because if one parent is affected by allergies, each child has a 30% chance of developing an allergy. Then if both parents have any type of allergy, the child has 70% of developing an allergy. Also if neither of the parents has allergies the chances of the child developing allergies is still 15%. I hope I didn’t confuse you with all these numbers, regardless of the percentage, your child can still develop allergies at any point in life thanks to the other two factors: chemicals and hygiene hypothesis.