Allergy is caused by a sensitivity response of the immune system to an allergy-causing agent called an allergen. The first signs of allergy are itching and swelling on the skin surface or nausea, vomiting, and diarrhea if the allergen was swallowed.

Some people are allergic to pollen grains or perfumes which lead to flu, a blocked nose and blocked respiratory system. You should know the specific substance your child is reacting to for better management of his or her allergy.

You will learn more about the scientific ways of dealing with allergy in this section, including how to manage it and also how to prevent it.