Allergic reaction may be found in up to 20% of the general US population, but by the age 6, 40% of the children in the United States have some sort of allergic problems. Although most of these children have respiratory problems, such as allergic rhinitis or bronchial asthma, many of those with allergies may also have atopic reactions to foods or medications. As antigens are slowly introduced into an infant’s environtment or diet, the child’s propensity to deal with these new substances may not be developed. In addition, children’s airways are small, their gastrointestinal tracts are not developed, and their immune systems are not ready to meet the challenges of these newly introduced proteins called allergens. Most responses are Gell and Coombs type 1 or immediate hypersensitivity reaction.