Cross-reactivity to metal compounds studied in guinea pigs induced with chromate or cobalt.

Multiple sensitivity to metals is often seen in humans. This may be due to cross-reactivity or to multiple sensitization. The pattern of cross-reactivity to some metal compounds was studied, using the guinea pig maximization test method. Animals were induced with K2Cr2O7 and CoCl2, respectively, and then challenged with K2Cr2O7, CoCl2, NiSO4, PdCl2 and RhCl3. No simultaneous reactivity was recorded. This supports the view that simultaneous reactivity in patients to nickel-cobalt and to chromate-cobalt is due to multiple exposure and sensitization, and not to cross-reactivity. The purity of the test compounds was analysed.