Ingredients in cleaning products can also cause a similar contact rash. “These types of skin reactions aren’t immediate,” says Dr. Hummell. “Initially, it may just look a little red or irritated. But over time you become sensitized to it, and within days, a more chronic rash may appear.” (In this way, it’s similar to a poison ivy reaction.)
Skin reactions like these generally don’t trigger life-threatening complications like throat swelling, heart problems, or asthma attacks, the way that other allergies can. But because they can cause serious discomfort and irritation, identifying the cause (and then avoiding it) is still important.
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 gastroinstestinal symptoms, including allergic eosinophilic esophagitis .