Inhibition of the sensitizing effect of carvone by the addition of non-allergenic compounds.

We have previously reported a reduction of sensitization to carvone in guinea pigs when adding non-allergenic, structurally related compounds simultaneously at induction. This study investigates the criteria needed to obtain a reduction of sensitization in contact allergy. Linalool, a non-sensitizer structurally unrelated to carvone, significantly reduced the sensitizing capacity of carvone in guinea pigs. The effect of different concentrations of inhibitors in mixtures with carvone was investigated. No significant differences in response were obtained between the concentrations explored. A possible anti-inflammatory effect from the inhibitory chemicals was investigated in vitro. No suppression of the immune system was seen. This study shows that a non-allergenic compound with a structure not resembling the hapten can reduce the sensitizing effect of the hapten. It indicates that reduction of an allergenic effect might occur in consumer products that are mixtures of different chemicals. Further studies with chemically unrelated compounds with and without allergenic effect are needed.