KOCH'S SUBCUTANEOUS TUBERCULIN REACTION 49 



cause there are non-tubercular individuals who respond to this quantity 

 of tuberculin. 



Most tuberculous persons react after a dose of o.ooi c.cm. to 0.005 

 c.cm. T.; those, however, who are very far advanced or who suffer from 

 severe cachexia, remain unresponsive to even much greater doses; in 

 addition, patients whose serum contains antituberculin, do not react be- 

 cause the inoculated tuberculin is quickly neutralized. 



According to Loewenstein the tuberculin reaction does not depend so 

 Loewenstein's much upon the quantity of the tuberculin, as upon the frequency that 

 Dosage it is injected. He, therefore, advises that the same amount, about 

 Scheme. 0.0002 c.cm. be inoculated four times during the course of twelve to 

 sixteen days. In by far the greater majority of tuberculous patients a 

 typical reaction appears after the third or fourth injection. The author has no per- 

 sonal experience with this method, but the reports of other authorities do not exhibit 

 as favorable results as those claimed by Loewenstein. 



The inoculation is always to be given subcutaneously, and the 

 Technique of back Qr b reast j s t h e best site for it. The dilution is made 

 j . . immediately before the injection, with physiological salt solu- 

 tion or 0.5 per cent, carbolic solution. 



In interpreting the result of the reaction one must exclude 



Value of rises of temperature due to extraneous influences such as 



Reaction. Angina, Influenza, etc. Furthermore there are individuals, 



especially hysterical ones, in whom any injection as such is 



apt to produce a rise of temperature. To guard against such a possibility 



an injection cf physiological salt solution should be made and thus quiet 



any suspicion of error. 



The diagnostic use of tuberculin is indicated when one is 

 Indications, dealing with adults who present clinical symptoms, or clinically 

 suspicious symptoms of tuberculosis, but who run no tem- 

 perature and tubercle bacilli cannot be found. 

 Tuberculin is contra-indicated in patients with high fever, 

 Contra- and during or shortly after hemoptysis or hematuria. In 

 'indications, epilepsy, marked cardiac or renal affection, arteriosclerosis, 

 diabetes, and similar conditions, inoculation should be under- 

 taken' only under the strictest indications and with great care. 



A positive general reaction means that the individual is infected with 

 tuberculosis, but does not throw any light upon the site, the extent, or the 

 prognosis of the infection. The focal reaction allows the diagnosis of the 

 position of the lesion. 



The Cutaneous Reaction. 



The cutaneous reaction was first introduced by v. Pirquet, who noticed 

 that by scarification of the skin and application of tuberculin, tuberculous 



