atopic definition medical
atopy. Definitions: 1. A genetically determined state of hypersensitivity to environmental allergens. Type I allergic reaction is associated with the IgE antibody and a group of diseases, principally asthma, hay fever, and atopic dermatitis.The definition information for atopy is provided by Stedman's.topy. Definitions: 1. A genetically determined state of hypersensitivity to environmental allergens. Type I allergic reaction is associated with the IgE antibody and a group of diseases, principally asthma, hay fever, and atopic dermatitis.