HYPERSENSITIVENESS 517 



individuals and the results which they report may be summarized 

 as follows : 



Funk and Huntoon's Results With OT and MA-100.— In 1930 

 Funk and Huntoon* performed intracutaneous tests in 441 indi- 

 viduals using; both Koch's old tuberculin and the new product 

 j\[A-100. In regard to the appearance of the reaction they say, 

 '"The reaction is usually an erythema surrounding an area of 

 edema, although occasionally the edema is larger in area than 

 tlie erythema, or rarely, edema without erythema. The erythema 

 may vary from a very faint blush to a dark red, may be diffuse 

 in character, or very sharply limited. The edema varies from a 

 barely perceptible (to the touch) thickening to a marked indura- 

 tion several millimeters in height. ' ' The reactions come on within 

 twenty- four hours; about half of them begin to fade before, and 

 all after, forty-eight hours. They state that pigmentation occurs 

 but is less likely to follow with the protein than when OT is used. 



Dosage Employed. — They adopted a dosage of 0.00001 c.c. of 

 OT and 0.0005 mg. for the MA-100. These respective tuberculins 

 were diluted so that 0.05 c.c. contained the test dose for the Man- 

 toux test. They used tuberculin syringes (1 c.c.) of the Luer type 

 with a number 24-gauge % inch needle. The level of the needle 

 was turned up, i.e., in line with the graduations. After washing 

 the anterior surface of the forearm with alcohol and drying it, they 

 inserted the needle into the skin until the bevel was completely 

 covered although dimly visible. The test dose contained in 0.05 

 c.c. of solution was then injected, producing a small wheal about 

 5 to 7 mm. in diameter. The arm was then wiped with alcohol. 



Reading the Reactions. — They made the first reading between 

 twenty-three and twenty-five hours after the injection and a second 

 reading after forty-eight hours. If the first reading was negative 

 they made a second test injection using 0.1 c.c. of the same dilution. 

 In other words, they doubled the dose for the second test. In read- 

 ing the reactions they noted the intensity of the color of the 

 hyperemia and measured the longest and shortest diameters of 

 liotli the erythema and edema. The latter information was recorded 

 in millimeters. 



The measurements of the reactions o])served in 218 individuals 

 positive to both OT and MA-100 showed an average diameter of 



♦Funk and Huntoon: J. Iniinunol. 19: 237. 1930. 



