Studies in Scarlet Fever

Abstract

In 1923, one of us (J. A. T.) noted that human placental serum blanched the rash of scarlet fever. Since then, we have carried out a comparative study of the intradermal reactions to placental serum and the corresponding reactions to scarlet fever antitoxin, maternal serum and convalescent scarlet fever serum. The effects of ether extraction, of filtration and of catalyzation on the blanching powers of the various serums were studied. METHOD OF PROCEDUREPlacental serum was collected at birth by milking the cord into sterile containers. Mother's serum was obtained twice, one week before and one week after the birth of the infant. All serum, placental or otherwise, was centrifugated ; the clear supernatant fluid was inactivated at 56 C. for two hours and then bottled. Convalescent scarlet fever serum was obtained at least twenty-one days after the acute illness had begun, and was likewise inactivated. When serum was extracted by ether, it was washed three times with ether and then filtered ; when it was filtered, a Berkefeld filter no. "W" * was used, and when it was catalyzed, 1 drop of normal serum was used as the catalyzing agent. was potent for three years, after which time it became infected with mold. In subsequent experiments, Squibb's commercial toxin was used.The only patients who received injections were those with good macular rashes. Injections were not made into patients whose rashes had been present for more than forty-eight hours, and most of the injections were done within twenty-four hours of the appearance of the exanthem. In each case, 0.5 cc. was injected unless otherwise noted. For convenience, the reactions were read as follows : + indi¬ cates 1 cm. of blanching; ++, 3 cm. of blanching; + ++, 4 cm. of blanching, and H-|-[--)-, 5 cm. of blanching. SUMMARYThe detailed observations are tabulated in the accompanying tables. The essential points may be summarized as follows :