In the course of previously reported1 studies on the therapeutic effect of "detoxified pertussis antigen" the value of a cutaneous test with pertussis "toxin" as an indicator of susceptibility to the disease was studied. At the same time the relation of the complement fixation test for pertussis to cutaneous sensitivity was examined.
Numerous investigators have attempted to demonstrate the reliability of an intracutaneous test, using either pertussis vaccines or extracts of Haemophilus pertussis. There have been conflicting reports in the literature in regard to cutaneous reactions with pertussis toxin. Some authors state that there is a definite relation between the results of cutaneous tests and immunity.2 Others3 obtained no correlation between intracutaneous reactions and state of immunity to H. pertussis. Toomey and his associates4 always found a local reaction after six hours in 680 persons tested with a pertussis filtrate grown on a specially prepared medium.