Allergenicity of aminobenzene compounds: structure-function relationships.

Six aminobenzene compounds (p-phenylenediamine, p-aminophenol, p-toluidine, p-sulfanilic acid, p-aminobenzoic acid, and p-nitroaniline) were used to correlate chemical structure and allergenicity. To obtain more quantitative data, the challenges were made at several concentrations. Utilizing for sensitization four 24 h occlusive patches in guinea pigs, we observed that compounds with activating chemical groups (-NH2, -CH3, -OH) were more potent sensitizers than compounds with deactivating groups (SO3H, COOH, NO2). This information should assist predictive identification of hair dyes, local anaesthetics and other aminobenzene structures that are more or less allergenic.