hypersensitivp:ness 533 



5. It may be temporarily removed by desensitizing the patient 

 or the same may occur as a result of massive infection. 



6. The reaction may be suppressed during an attack of an 

 acute exanthematous disease or during labor and the puerperium. 



7. In some 3 to 5 per cent of the cases of miliary tuberculosis 

 the reaction to tuberculin OT is absent. 



8. The typical tuberculin reaction is of the delayed type and 

 persists for several days. It is characterized by edema, more or 

 less hyperemia and infiltration. Microscopically there is an initial 

 neutrophile response followed by a preponderance of mononuclear 

 over polynuclear cells. The cells are for the most part of vascular 

 origin. 



9. A similar reaction is demonstrable in protein anaphylaxis 

 when skin tests are made on the fourth to the sixth day after the 

 sensitizing dose is administered. When skin tests are made after 

 the sixth day the reaction is immediate and of the anaphylactic 

 type. The latter reaction is characterized by hyperemia, wheal 

 formation, and an exudate containing a preponderance of neutro- 

 philes. 



10. While antibodies have not been detected in tuberculin 

 allergy, there is some evidence which suggests that the tuberculin 

 reaction is mediated by an antigen-antibody mechanism. 



11. It is suggested by Dienes that in tuberculosis there is a 

 fixation of the early anaphylactic type of response. 



12. In public health work the tuberculin test is of value in 

 screening out of a large group of individuals for further study, 

 those who have healed, potentially active, or active lesions of 

 tuberculosis. 



13. One cannot differentiate between primary and reinfection 

 types of tuberculosis by means of the tuberculin test. 



14. Likewise the severity of the reaction cannot be correlated 

 with the type of lesion present. 



15. Corper and Cohn report that the symi)toms of tuberculo- 

 allergic intoxication are different from those of tuberculo-anaphy- 

 laxis. They also state that histaminase does not prevent or modify 

 the sjonptoms of either. 



16. The purified protein derivative of tuberculin prepared in 

 accordance with tlu; recommended procedure of Seibert is gener- 

 ally regarded as superior to OT. 



