HYPERSENSITIVENESS 561 



bodies or reagins for fish proteins by injecting a small amount of 

 his serum intracutaneously into the forearm of a nonsensitivc 

 person. A few hours later, when the area thus injected was tested 

 with an extract of fish proteins, a positive skin reaction occurred. 

 This phenomenon, which indicates the presence of reagins in serum, 

 is called the Prausnitz-Kiistner or P-K reaction. Coca and Grove 

 state that only about 80 per cent of normal skins are receptive. 



In 1937 Cowie reported upon a scries of individuals who were 

 clinically sensitive but skin negative to certain food allergies. He 

 stated that the intradermal injection of such a patient's own serum 

 into his skin rendered the injection site sensitive to the allergin. 

 This he called autopassive transfer. Martin (1940) was unable to 

 confirm Cowie 's conclusions. On the contrary he states that the 

 patient's own serum has an inhibitory rather than an enhancing 

 effect. 



Sensitization Throug-h Alimentary and Respiratory Tracts and 

 Through Placenta, — Walzer (1927) made use of the Prausnitz- 

 Kiistner reaction to ascertain whether the exciting agent is ab- 

 sorbed through the mucous membrane of the intestine. He injected 

 serum from an egg-sensitive patient and from two fish-sensitive 

 patients intracutaneously into the forearms of nonsensitivc in- 

 dividuals. The following morning he fed the recipients egg and 

 fish, respectively, and observed redness and swelling develop at the 

 site of the serum injections. 



In 1936 Gray and Walzer reported on the absorption of un- 

 digested peanut protein following oral and intraduodenal admin- 

 istration. They have also found (1940) this protein to be absorbed 

 from the rectum. 



Gay and Chant passively sensitized to ragweed an area in the 

 skin of the forearm of a nonsensitivc individual and after an ade- 

 quate incubation period had elapsed they injected ragweed pollen 

 extract intradermally into the opposite forearm. This caused a 

 positive reaction characterized by erythema, edema, and itching 

 in the area that had been passively sensitized. According to Gay 

 and Chant this reaction was produced by ' ' contralateral injection. ' ' 



Ulrich (1918) and Eatner and Gruehl (1929) offer evidence 

 which indicates that specific sensitization may develop as a result 

 of absorption through the respiratory mucous membrane. When 

 one considers the amount of exposure to pollen and various finely 



