A genetic predisposition to the development of certain allergic diseases has been recognized since the early 1900s. In 1916, Cooke and van der Veer1 reported that almost 50% of patients with allergic rhinitis and asthma had a positive family history of similar illness. In 1923, Coca and Cooke2 coined the term atopy to describe immediate hypersensitivity reactions that had an inherited tendency. Their classification scheme was later criticized because of the mistaken belief that atopic diseases were transmitted in an autosomal dominant fashion. Coca and Cooke believed that reaginic (allergic) antibodies played a central role in disease pathogenesis, although they failed to recognize that these reactions were dependent on antigen-antibody interactions. Nonetheless, the term atopy has persisted in the medical literature and is often used synonymously with the terms allergy and immediate hypersensitivity. Consensus regarding a precise definition for atopy is lacking.3,4 Since the discovery of IgE and the elucidation of the mechanisms involved in immediate-type hypersensitivity reactions, most authors use the term to describe the inherited tendency to develop IgE antibodies to specific allergens. The inherited tendency to produce allergen-specific IgE predisposes individuals to the development of certain diseases, including asthma, allergic rhinitis, and atopic dermatitis.
MacLean JA, Eidelman FJ. The Genetics of Atopy and Atopic Eczema. Arch Dermatol. 2001;137(11):1474-1476. doi:10.1001/archderm.137.11.1474