Reexamination of the Criteria for Reading of Dick Reaction

Abstract

The frequency diagram of Dick reaction according to the intensity was analyzed by the author in order to establish a reasonable criteria for reading of the reaction. Toxin (Lot No.3 and 4) of S₈ strain, the representative one in our countly and Toxin (Lot No.6) of a new epidemic strain 55-16 were used in this investigation.These toxins, dissolved in the usual buffer solution, 0.1 cc of which corresponded to ISTD, were injected to 1, 401 pupils of primary schools in a village where epidemics of scarlet fever were not persistent, 1, 003 pupils of primary schools in a town immediatly after a epidemic of the disease, 1, 161 pupils of primary schools in a town, children after the disease and hospitalized scarlet fever patients. Reddening was observed in all the cases, no side-reaction, or induration, or double reddening being noticed. The diameter of reddening caused by these toxins were distributed between 4-36 mm, odemonstrating a diagram with a peak at 10-15 mm. Lot No.3 and 6 differing in neutralixation demonstrated only in 50% of the children the same reddening diameter, when injected simultaneously in an individual. The reaction after the disease converted to negative only in 50% of the cases.
These data led the author to the following criteria:
The reading of Dick reaction should be made after 24 hrs, using the reddening as an indicater. All the cases with reddening are considered positive, however, those with non-specific reaction due to contrast solution must be classified into pseudopositive. Concerning the toxin, it must be prepared not from only one strain, but Irom several strains containing at least the two toxins mentioned above.