242 THE PRINCIPLES OF IMMUNOLOGY 



easily read and is sufficiently sensitive to provide all the information that 

 can reasonably be expected to accrue from the tuberculin test. 



Luetin Reaction. Numerous attempts were made following the 

 announcements of the Von Pirquet cutaneous tuberculin test, to devise 

 a similar test for syphilis. It was found, however, that extracts of 

 normal organs produced the same effects as those from syphilitic organs. 

 It was not until Noguchi cultivated the treponema pallidum in vitro that 

 a preparation of the causative agent could be prepared. Noguchi pre- 

 pared a suspension of the organisms together with the ascites-kidney 

 agar upon which they were grown. Cutaneous reactions were unsat- 

 isfactory, and it was found necessary to make the test by intracutaneous 

 injection of the material. The reaction appears in papular or pustular 

 form in from twenty-four to forty-eight hours or later. It was found 

 by Sherrick that patients receiving potassium iodide give positive reac- 

 tions and by Cole and Paryzek that similar reactions follow the ad- 

 ministration of bromides. Although Noguchi found that injection of 

 the culture medium without the organisms did not produce reactions, 

 Stokes as well as Kolmer, Matsunami and Broadwell were able to pro- 

 duce reactions by injecting agar. Although Noguchi and others re- 

 ported high percentages of positive reactions in known syphilitics, yet 

 in the hands of some workers the number has been only about 50 per 

 cent. The test is not widely employed and apparently gives no informa- 

 tion that cannot be obtained equally well or better from the Wasser- 

 mann test. It has been suggested that the luetin test may be of value 

 in late syphilis, where the Wassermann test is negative, but the large 

 non-specific element of this skin reaction does not tend to place much 

 reliance upon the test. 



Cutaneous Reactions in Typhoid Fever. Several of the earlier 

 studies on this subject were concerned with reactions in the conjunctiva. 

 Chatemesse and also Austrian were able to obtain positive ophthalmo- 

 reactions in a large percentage of cases of typhoid fever and prac- 

 tically no positive reactions in other individuals. Although Kraus could 

 not obtain skin reactions, Zupnik and also Floyd and Barker obtained 

 encouraging results. Gay and Force have employed a substance which 

 they name typhoidin, prepared from bacillus typhosus, according to the 

 method employed for the preparation of old tuberculin. The prepara- 

 tion was modified subsequently by Gay and Claypole. The typhoidin 

 is applied in abrasions of the skin as with the cutaneous tuberculin test. 

 These investigators found a high percentage of positive reactions in 

 individuals who had recovered from typhoid fever as well as those 

 who had been vaccinated and recommend it as a method for determining 

 the presence of immunity to typhoid fever. Kilgore has studied the 

 test clinically and finds that the test is unreliable because of unavoidable 

 variations in the application of the test, indefiniteness of the readings 

 and the large non-specific element in the reaction. 



Cutaneous Reactions to Gonococcus Infections. These reactions 

 are particularly applicable to deep-seated and chronic infections with 

 the gonococcus. Irons found local and general reactions following the 



