IOI2 ATOPY 



riod of some weeks; furthermore, this attainable maximum of tolerance is often too 

 low to permit the injection of the usual therapeutic dose of serum. Hence, if the 

 question of a therapeutic or prophylactic injection of antitoxic horse serum is raised 

 with regard to a known horse-asthmatic patient, the physician should refuse to ad- 

 minister the serum and should not attempt what is loosely called "desensitization." 



Instances of serious and even fatal reactions following a reinjection of horse serum 

 in non-atopic persons have been reported. The fatal issue for much the greater part 

 followed intravenous or intraspinal reinjection. What percentage of reinjections re- 

 sult in dangerous reactions is not known (exact information upon this question is 

 needed), but it must be small — so small that the risk should be taken without hesita- 

 tion when the condition of the patient requires the specific treatment. In such cases, 

 the subcutaneous route should be usually preferred, although even this precaution 

 should be waived when the patient's condition urgently requires the more efifective 

 intravenous administration. 



The observations of Park,' whose opinion has been stated in the foregoing para- 

 graph, expose the inadequacy of the cutaneous test as a means of determining the 

 individual's susceptibility to a reinjection. In his experience, even a marked skin re- 

 action could be elicited in persons who later tolerated the intravenous injection of 5 

 or 10 cc. of serum. 



The procedure of "desensitization," which is ineffective in atopic serum h3q)er- 

 sensitiveness, fails also in serum disease. This conclusion has been discussed by the 

 writer^ with respect to ordinary serum disease. It is confirmed by the experience of 

 Louis Tuft, about to be reported. The patient, after a three weeks' interval, following 

 the previous administration of serum, was "desensitized" over a period of two and 

 one-half hours by the intramuscular injection of 8.0 cc. of serum. Thereupon not 

 more than 10 cc. of the serum was slowly injected into the vein. The patient com- 

 plained suddenly of a burning sensation, and collapsed, dying shortly afterward. 



From the foregoing, it seems evident that, where reinjection of therapeutic serum 

 is urgently indicated, it is useless to apply the cutaneous test or the procedure of 

 desensitization as precautionary measures. The physician must be governed in such 

 a situation wholly by the exigencies of the patient's condition. 



HYPOSENSITIZATION 



After Wolff- Eisner^ and Meltzer^ had expressed the view that hay fever and asth- 

 ma were expressions of hypersensitiveness in human beings, there were several inde- 

 pendent attempts made in this country, as well as in Europe, to apply the principle 

 of desensitization in the treatment of these conditions, and it was found by Noon^ 

 and his numerous successors* that the procedure applied in hay-fever subjects and 



' Park, W. H.: /. Immunol., 9, 17. 1924. 



^ Coca, A. F.: Tice'sPmc/Zce of Medicine, i, 107. Hagerstown, Md.: W. F. Prior Co., Publishers, 

 1920. 



3 Wolff-Eisner, A. : Das Ileiijichcr. 1906. 



1 Meltzer, S. J.: 7./1.M./1., 55, 1021. 1910. sNoon, L.: Lancet, i, 1572. 1911. 



''Freeman, J.: ibid., 2, 814. 1911; Clowes, G. H. A.: Proc. Soc. Exper. Biol. ^ Med., 10, 69. 

 1913; Koessler, K. K.: Forscheimer's Therapeusis, 5,671. 1914. 



