ABSTRACT
BACKGROUND: Preservatives are an unfortunately common cause of allergic contact dermatitis (ACD). Often, this is in association with exposure to cosmetics or medicaments. Recently, a quantitative risk assessment (QRA) approach to the quantitation of safe exposure levels for sensitizers has been promulgated as a more effective tool for the identification of acceptable levels of potential sensitizers in consumer products. OBJECTIVE: To assess this QRA approach, which facilitates the prediction of acceptable exposure levels to skin sensitizers in consumer products, levels that are normally below the threshold for the induction of skin sensitization. METHODS: Retrospective QRA analysis on four preservatives in five consumer product types. RESULTS: The analysis shows that functional levels of preservatives may be somewhat above an ideal exposure level for some product types, an outcome that is consistent with the clinical picture. CONCLUSION: QRA represents a new tool that in the future should be used in combination with the assessment of microbiologic protection needs of specific product types to limit the problem of preservative ACD.
Subject(s)
Allergens/toxicity , Cosmetics/toxicity , Dermatitis, Allergic Contact/diagnosis , Risk Assessment/methods , Administration, Topical , Allergens/analysis , Consumer Product Safety , Cosmetics/analysis , Dermatitis, Allergic Contact/etiology , Dermatitis, Allergic Contact/pathology , Dermatitis, Allergic Contact/prevention & control , Dose-Response Relationship, Drug , Environmental Exposure/prevention & control , Environmental Monitoring/methods , Female , Humans , Male , Research Design , Skin/drug effects , Skin Tests/methods , United KingdomABSTRACT
Whereas many investigations of the variables associated with the elicitation of allergic contact dermatitis have been undertaken, to the point where we can begin to predict the likelihood of elicitation occurring in a given situation, the same is not true for the induction of skin sensitization. Studies have demonstrated that increasing dose has an impact; in an experimental setting, a number of variables received attention some decades ago. However, in the work reported here, the relative importance of the frequency and the duration of exposure is highlighted. In an investigation using a human repeated insult patch test, it was demonstrated that reduction of the exposure duration from 48 hr to 5 min decreased the rate of sensitization to 1% p-phenylenediamine (PPD) from 54% to 3%. However, in an extended clinical study, it was observed that infrequent but longer duration and higher concentration exposure to PPD was significantly less likely to induce sensitization compared to more frequent, short duration, and lower concentration exposure. Detailed statistical analysis of the results indicated that the most important factor driving the induction of skin sensitization was the number of exposures.
