[Sensitisation to p-Phenylenediamine. Effects of metabolism and individual susceptibility].

Due to its constant exposure to small molecular weight compounds, the skin is a major target for allergic reactions. Para-phenylenediamine (PPD) is a common and strong contact allergen. Recent studies have revealed new aspects of steps involved in sensitization and allergic contact dermatitis to PPD, giving insight into the cutaneous metabolism of small molecular compounds and its effect on activation and deactivation of immunogenic substances. Molecular epidemiological studies have suggested that polymorphisms in genes encoding cytokines (e.g. TNF-alpha) or metabolizing enzymes (e.g. N-acetyltransferase) may have influence on these mechanisms and the individual susceptibility for sensitization.