592 ANAPHYLAXIS IN RELATION TO INFECTION AND IMMUNITY 



practically devoid of danger, providing that a careful technic is ob- 

 served. 



Regarding the dangers of the conjunctival test, opinions differ. 

 There can be no doubt, however, but that distressing sequelae, such as 

 severe recurring conjunctivitis, phlyctenular conjunctivitis, and corneal 

 ulcers with permanent opacities have resulted from the use of this test. 

 Most of the unfavorable results have followed instillation in already 

 diseased eyes, or of too strong solutions, but this is not true of all cases. 

 As will be pointed out further on, in the first instillation not over 

 1 per cent, of old tuberculin should be used, and a second instillation 

 should never be made in the same eye for at least several years. 



Since old people are especially prone to conjunctival inflammation 

 and corneal ulceration, it is probably better to exclude them from the 

 test. Another drawback to this test is the possibility of a "flare up" 

 in the eye following subsequent subcutaneous administration of tuber- 

 culin, either for diagnostic or therapeutic purposes. Hamman and 

 Wolman, however, do not consider this dangerous, and have observed 

 but two cases in an extensive experience. 



THE SUBCUTANEOUS TUBERCULIN REACTION 



As has been stated repeatedly, the subcutaneous injection of tu- 

 berculin is resorted to at the present time mainly for the purpose of 

 eliciting a focal reaction, and, as a rule, this is more easily appreciable 

 when the general reaction is well marked. // tuberculin is used simply 

 to establish whether or not a person is hypersensitive, this fact may be 

 demonstrated by employing much smaller doses, as by the cutaneous, intra- 

 cutaneous, or conjunctival tests, the patient being spared the discomfort 

 of the constitutional symptoms. 



Variety of Tuberculin. Koch's old tuberculin is now used almost 

 exclusively. The technic of its preparation is given in the chapter on 

 Tuberculin Therapy. 



Manufacturing chemists usually market this tuberculin in a series 

 of dilutions, labeled and accompanied by explicit directions, so that the 

 physician may administer practically any dose desired by injecting 

 so many minims of such or such dilution. Otherwise a series of 

 dilutions are readily prepared in the physician's office or dispensary, 

 according to the method followed by Hamman and Wolman : 



(a) Seven wide-mouthed bottles of about from 12 to 15 c.c. ca- 

 pacity, and fitted with ground-glass or rubber stoppers, are sterilized, 

 labeled, and numbered from 2 to 8. 



