TUBERCULIN REACTION 629 



tests by a review of the literature, it must be remembered that results 

 will vary according to the portion of the body inoculated, as sensitive- 

 ness of the cells varies in different parts of the body, and there are indi- 

 vidual differences in various persons that are difficult or impossible to 

 explain. . 



By comparing the figures obtained as the result of different tests 

 upon the same person with the relative frequency of individual tests, 

 Hamman and Wolman 1 have drawn the following conclusions: 



"1. The intracutaneous and subcutaneous local tests are the most 

 delicate we possess. They reveal practically the full percentage of 

 tuberculosis-infected individuals. 



"2. In the order of their sensitiveness, the tests arrange themselves 

 as follows: 



Intracutaneous Test. 



Subcutaneous Local Test. 



Cutaneous Test. 



Subcutaneous Test. 



Percutaneous Test. 



Conjunctival Test. 



"3. There is a definite but not a constant relation between the vari- 

 ous tests. An individual reacting to the conjunctival test will, as a rule, 

 give all the others, but not always. The cutaneous or the subcutaneous 

 tests may be negative when the conjunctival is positive. The sub- 

 cutaneous positive when the cutaneous is negative, etc. Some of the 

 unusual variations may, no doubt, depend upon faulty technic in per- 

 forming the tests, but all can certainly not be thus explained. Local 

 changes in sensitiveness and variation in the facility of absorption are 

 probably factors, but the exact conditions are not understood. 



"4. We have been unsuccessful in an attempt to make the cutaneous 

 test with different strengths of tuberculin equivalent to the conjunctival 

 test." 



Although the subcutaneous test may bedangerous on account of the 

 harm that may result from too severe focal reactions, yet, when carefully 

 conducted, it is frequently the method of choice, especially in the diag- 

 nosis of an obscure pulmonary lesion, and in bone, joint, skin, and other 

 local infections, where the focal reaction may be detected by direct 

 examination. It is to be emphasized, however, that the absence of 

 focal changes during a constitutional reaction does not exclude the tu- 

 berculous nature of a suspected lesion. In children, as shown by Hamill, 

 1 Tuberculin in Diagnosis and Treatment, 1912, Appleton, 167. 



