Before revision: A child's allergy is an immune system reaction to a foreign substance, or allergen, that is considered harmless to most.
After revision: MorbidityChildren affected by allergies in the developed world: 1 in 13 have eczema 1 in 8 have allergic rhinitis 3-6%DIF > are affected by food allergyChildren in the United States under 18 years of age: Percent with any allergy: 27.2%DIF > Percent with seasonal allergy: 18.9%DIF > Percent with eczema: 10.8%DIF > Percent with food allergy: 5.8%DIF >Children in the United Kingdom: 1 in 6 with eczema 1 in 5 with allergic rhinitis 7.1%DIF > of breast-fed infants who develop food allergiesPathophysiologyA child's allergy is an immune system reaction to a foreign substance, or allergen, that is considered harmless to most.