4 8 



TUBERCULIN DIAGNOSIS 



CHART i. Example of a diag- 

 nostic tuberculin reaction. 



The dose chosen at the first injection is 

 o.ooi c.cm. T. Very weak individuals, i.e., 

 those in an advanced stage of tuberculosis or 

 those who have experienced a recent hemopty- 

 sis, as well as children, should receive an initial 

 dose of only o.oooi c.cm. T. Bandelier and 

 Ropke, who have a wide experience in this field, 

 advise 0.0002 c.cm. T. as the primary dose. 



Few patients show a distinctly positive 

 fever reaction even with this small dose; by a 

 positive reaction is meant an increase in the 

 temperature so that the latter is at least 0.5 C. 

 higher than the highest point before the injection. 

 If the temperature has not increased, the re- 

 action is negative, and after an interval of two 

 to three days of normal temperature the second 

 inoculation of 0.005 c.cm. T. is given. If as 

 happens occasionally after the first inoculation 

 there is a doubtful reaction, i.e., there is an in- 

 crease of 0.2 to 0.3 C. then the dosage at 

 the second injection should not be increased 

 to 0.005 c.cm., but the same amount o.ooi 

 c.cm. T. is to be repeated. In a tuberculous 

 individual this repeated injection of o.ooi c.cm. 

 frequently results in a distinctly positive reac- 

 tion, while in a non-tuberculous patient instead 

 of the former doubtful, a distinct negative re- 

 action is obtained. 



The general rules given for the first inocula- 

 tion also apply to the second with 0.005 c.cm. 

 In a doubtful reaction with this dose, one 

 does not directly proceed to the o.oi c.cm. 

 dosage, but the 0.005 c.cm. dose is repeated 

 and only after a negative reaction with the 

 repeated 0.005 c.cm. dose is the o.oi c.cm. in- 

 jected (see accompanying Chart i). This rep- 

 resents the maximum amount of tuberculin to 

 be used for diagnostic purposes. Koch advises 

 repetition of this dose if no reaction is ob- 

 tained. The majority of authorities, however, 

 abstain therefrom. In fact some investigators 

 claim that a reaction obtained after inoculation 

 of o.oi c.cm. cannot be considered specific, be 



