Concomitant anaphylactic sensitization and contact unresponsiveness following the infusion or feeding of picryl chloride to guinea pigs.

Guinea pigs receiving one large dose of picryl chloride by the intravenous or oral routes commonly develop circulating antibody demonstrable by passive cutaneous anaphylaxis or by active anaphylaxis. They often concommittantly become unresponsive to the induction of delayed contact hypersensitivity by intracutaneous injections. Erythrocytes obtained from guinea pigs after infusion or feeding of picryl chloride may be used to sensitize other animals when injected with adjuvant. It is concluded that guinea pigs may be anaphylactically sensitized to simple chemicals by the intravenous and oral routes if a sufficient dose is administered.