448 THE TUBERCLE BACILLUS GROUP 



the tubercle bacillus depends upon the fact that the tuberculous 

 subject is sensitized to the proteins of the tubercle bacillus as the 

 result of infection with this organism. 1 The presence of the proteins 

 of the tubercle bacillus and perhaps other products of growth of the 

 tubercle bacillus stimulate certain body cells of the host to produce 

 specific proteolytic ferments which dissolve these proteins within the 

 body. 2 When tuberculin is introduced into the tuberculous host these 

 specific proteolytic ferments liberate from the tuberculin a poisonous 

 cleavage product which has three specific effects: a focal effect, 

 characterized by intense irritation and inflammation around the tuber- 

 culous foci, a local effect, and a general effect which is characterized 

 by a rise of temperature and other general systemic reactions. The 

 tuberculin reaction is an anaphylactic reaction according to Vaughan. 3 



4. Technic of the Tuberculin Reaction. 4 The tuberculin reaction 

 elicited in man by the introduction of tuberculin is of two types, 

 depending upon the method of injection employed. If introduced 

 subcutaneously so that the tuberculin enters the lymph or blood 

 streams, even in minute amounts, the reactions consist of three rather 

 distinct phases: a general, a local, and a focal reaction respectively. 

 If, on the contrary, the injection is purely superficial in the epidermis 

 or on the conjunctiva the reaction is almost exclusively local. 



(a) The Subcutaneous Reaction ( Koch) . The characteristic response 

 following the subcutaneous injection of appropriate amounts of old 

 tuberculin is a generalized reaction consisting of a rise in temperature 

 of at least one-half a degree above the highest temperature exhibited 

 before the inoculation. This rise in temperature usually begins twelve 

 to eighteen hours after the injection; it may be delayed to twenty- 

 four or even forty-eight hours. The temperature should be taken at 

 half-hourly intervals. There is frequently an initial chill following 

 the introduction of tuberculin and in addition malaise, headache and 

 restlessness; even nausea or vomiting may be observed. The focal 

 reaction consists essentially of hyperemia and a distinct inflammatory 

 reaction around active foci. In superficial foci, as in lupus, this 

 inflammatory reaction may be distinctly seen, and in deeper foci 



1 For discussion of theories of the tuberculin reaction, see Kuthy and Wolff-Eisner, 

 Die Prognosenstellung bei den Lungentuberkulose, Berlin and Vienna, 1914. 



2 White, Jour. Med. Research, 1914, xxx, 393, has shown that lipoids of the tubercle 

 bacillus neither sensitize nor induce anaphylaxis in experimental animals. 



3 Protein Split Products, Philadelphia, 1913. See Baldwin, Yale Med. Jour., February, 

 1909, for excellent summary of present status of subject. 



4 The diagnostic and particularly the therapeutic use of tuberculin requires much 

 skill and experience. For details, see Baldwin and Brown, Osier's Modern Medicine, 

 iii, 137, 361. 



