Five major allergenic proteins from the egg of the domestic chicken ("Gallus domesticus") have been identified; these are designated Gal d 1-5. Four of these are in egg white: ovomucoid (Gal d 1), ovalbumin (Gal d 2), ovotransferrin (Gal d 3) and lysozyme (Gal d 4). Of these, ovomucoid is the dominant allergen, and one that is less likely to be outgrown as children get older. Ingestion of under-cooked egg may trigger more severe clinical reactions than well-cooked egg. In egg yolk, alpha-livetin (Gal d 5) is the major allergen, but various vitellins may also trigger a reaction. People allergic to alpha-livetin may experience respiratory symptoms such as rhinitis and/or asthma when exposed to chickens, because the yolk protein is also found in live birds. In addition to IgE-mediated responses, egg allergy can manifest as atopic dermatitis, especially in infants and young children. Some will display both, so that a child could react to an oral food challenge with allergic symptoms, followed a day or two later with a flare up of atopic dermatitis and/or gastrointestinal symptoms, including allergic eosinophilic esophagitis.