- 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. [G. atopia, strangeness, fr. a- priv. + topos, a place]
* * *at·o·py 'at-ə-pē n, pl -pies a prob. hereditary allergy characterized by symptoms (as asthma, hay fever, or hives) produced upon exposure esp. by inhalation to the exciting environmental antigenatop·ic (')ā-'täp-ik, -'tō-pik adj
* * *n.a form of allergy in which there is a hereditary or constitutional tendency to develop hypersensitivity reactions (e.g. hay fever, allergic asthma, atopic eczema) in response to allergens (atopens). Individuals with this predisposition - and the conditions provoked in them by contact with allergens - are described as atopic.
* * *at·o·py (atґə-pe) [Gr. atopos out of place] a genetic predisposition toward the development of immediate (type I) hypersensitivity reactions against common environmental antigens (atopic allergy). The most common clinical manifestation is allergic rhinitis; bronchial asthma, atopic dermatitis, and food allergy occur less frequently.
Medical dictionary. 2011.