CHAPTER LXXV 

 ATOPY 



ARTHUR F. COCA 



Cornell University Medical College 



The subject assigned for review to the writer by the editors of this volume does 

 not, in its present state, lend itself to categorical exposition, because its very existence 

 as a pathological-physiological entity, separable from the other phenomena of hyper- 

 sensitiveness, is generally doubted. The general unwillingness to approve the separa- 

 tion of atopic hypersensitiveness from the other forms is due not only to differences of 

 opinion as to the interpretation of accepted findings, but also, perhaps, to the lack of 

 confirmation of a number of observations that have been used by the writer to char- 

 acterize the atopic mechanism. 



This situation obliges the reviewer to adopt a controversial attitude and also to 

 refer, by way of comparison or contrast, to some other forms of hypersensitiveness, 

 such as anaphylaxis and ordinary serum disease, 



DEFINITION 



The term "atopy" (droTrta, "a strange disease")^ has been used to designate 

 certain clinical forms of hypersensitiveness which occur, so far as is known, only in 

 human beings, and which are subject to inheritance. 



The clinical forms included in this category are asthma and hay fever. While it 

 is thought probable that other forms, such as eczema and certain forms of drug and 

 -food idiosyncrasy, will ultimately be added to these two, more information is needed 

 before this can be done, 



ATOPIC INHERITANCE 



The separation of this group of hypersensitiveness from the others was made pos- 

 sible largely by the studies of Cooke and Vander Veer,^ as well as the confirmatory 

 ones of June Adkinson^ and of Spain and Cooke.^ These investigators have shown in 

 two ways the controlling influence of heredity in the establishment of bronchial asth- 

 ma and hay fever: First, by the observation that, when one of these conditions oc- 

 curred in both the paternal and the maternal antecedents, their incidence among the 

 offspring was decidedly greater than it was when only one line was affected, or when 

 the family history on both sides was negative in this respect; and, second, by the ob- 

 servation that the first appearance of the atopic symptoms occurs much earlier among 

 the children subject to a bilateral atopic inheritance than it does among those with a 

 unilateral or negative family history, 



' Coca, A. F., and Cooke, A. R. : J . Immunol., 8, 163. 1923. 



^ Cooke, R. A., and Vander Veer, A.: ihid.., i, 201. 1916. 



3 Adkinson, J.: Genetics, 5, 363. 1920. 



'• Spain, W. C, and Cooke, R. A.: J. Immunol., g, 521. 1924. 



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