ABSTRACT
In 1923 Coca and Cooke (1) introduced the term “atopy” to designate phenomena of hypersensitivity in humans. Atopy was adapted from the Greek word meaning “out of place” or “strange disease.” Atopy in the concept of Coca and Cooke is (1) hereditary, (2) limited to a small group of human beings, (3) different from anaphylaxis, referring to a lack of protection, and allergy, meaning an altered reactivity, both of which can also be induced experimentally in humans and in animals, (4) qualitatively an abnormal response occurring only in particular individuals (atopics), (5) clinically characterized by hay fever and bronchial asthma, and (6) associated with immediate-type (flare-and-wheal) skin reactions. The authors wanted to describe a familial or hereditary tendency-which does not occur in normals-to become sensitized in a natural way to certain substances in the environment, e.g., house dust, pollen, or food, and to develop hypersensitivity reactions such as hay fever and asthma, which are associated with immediate-type (flare-andwheal) skin reactions. At this time Coca and Cooke were evidently unaware of the work of Prausnitz and Küstner (2), published in 1921, about the passive transfer of immediate hypersensitivity in humans by serum. However, 2 years later Coca and Grove (3) defined the “atopic reagins” as the specifically
* Current affiliation: University Hospital, Zurich, Switzerland.
