72 PROTEIN THERAPY 



Concerning the Specificity of Focal Reactions. Perhaps the 



fact that the focal reaction is not a specific reaction must first 

 be emphasized. Practically every inflammatory focus, irrespective 

 of its etiology, will react (focal activation) to tuberculin as well 

 as to a great variety of other agents, chemical or biological in 

 character. Investigators in tuberculosis have long recognized the 

 fact that the tuberculous lesion responds with a focal reaction to a 

 variety of substances. Baldwin mentions nucleoprotein, nuclein, al- 

 bumoses, cinnamic acid, cantharidin, pilocarpin. Fishberg adds potas- 

 sium iodid and creosote. But the recognition that nontuberculous 

 inflammatory foci will likewise respond to such agents has only been 

 discussed in recent years. Perhaps the paper of Schmidt is of 

 greatest value in this connection. 



Schmidt began his observations on the Poncet type of arthritis. 

 This tuberculo-toxic form of disease exhibits a well-marked focal re- 

 action following the injection of tuberculin that is, the joint be- 

 comes more painful, and swollen, there is an increased limitation of 

 motion and the tissues become hyperemic. This stage is later fol- 

 lowed by improvement in the clinical picture (the negative phase 

 is followed by a positive one), the end results usually being an 

 improvement over that obtaining before the tuberculin injec- 

 tion. 



But Schmidt found that if instead of injecting tuberculin, milk was 

 used, he obtained exactly the same reaction at the site of the lesion, 

 during the same period of time, and with the same positive phase 

 following in the wake of the reaction (i. e., a therapeutic effect) . Fur- 

 ther, when he turned to nontuberculous joint lesions and injected 

 minute doses (.001 gm.) of Old Tuberculin (relatively rich in nonspe- 

 cific proteins) he obtained a similar focal reaction. 



Classification of Focal Reactions. The German clinicians have 

 gathered considerable data concerning the reactions that follow milk 

 injections (used merely as a convenient nonspecific protein) and 

 Schmidt has arranged the following groups in which there is a re- 

 sponse with a typical focal reaction following milk (and other) injec- 

 tions: 



I. Inflammatory foci of infectious origin. 



II. Localized inflammatory processes endogenous or traumatic in 

 origin. 



III. Diatheses. 



I. INFLAMMATORY Foci OF INFECTIOUS ORIGIN. Classified under 

 the first group we include pulmonary foci of tuberculous origin. 



Schmidt and Kraus, Petersen, Holler, Dollken and others have 

 called attention in recent papers to this phenomenon. Proteoses, 

 iodids, milk, nucleins and other agents will bring about a focal re- 



