Modified short-term guinea pig sensitization tests for detecting contact allergens as an alternative to the conventional test

The conventional adjuvant and patch test (APT) method of guinea pig sensiti zation testing was modified in 2 ways, s-APT and s-APT(2), in order to shor ten the test period. These short-term test methods consist of 72-h closed a pplication of test material with intradermal injection of emulsified Freund 's complete adjuvant (E-FCA) for Ist induction, 48-h closed application of test material with (s-APT) or without (s-APT(2)) intradermal injection of E -FCA on the 7th day for 2nd induction, and open application on the 14th day for challenge. They were compared with conventional APT by using 8 allerge nic chemicals (formaldehyde, nickel sulfate, cobalt sulfate, ethyl-p-aminob enzoate (benzocaine), isoeugenol, 2-mercaptobenzothiazole, 2,4-dinitrochlor obenzene (DNCB) and 1-phenylazo-2-naphthol (Sudan I)). The short-term metho ds gave similar results to those of conventional APT in terms of mean respo nse, sensitization rate and sensitization potency (challenge concentration that induces a mean response equal to 1.0). Thus, our short-term methods, w hich are capable of evaluating skin sensitization within 17 days, are suffi ciently sensitive to detect potentially hazardous contact allergens.