The marketing of widely used consumer products inevitably results in some reports of adverse dermatologic reactions which are tentatively attributable through medical history to the use of these products. Just as it is important for manufacturers to perform thorough premarket safety testing, it also is important for them to investigate these reported reactions to confirm the safety of the product under widespread use conditions. This report describes the results of such a follow-up investigation into 300 adverse reaction reports obtained during the first year of marketing of a new laundry product. The results of diagnostic patch and prick tests, controlled reuse testing, and definitive diagnoses by physicians (mostly allergists and dermatologists) demonstrated that this product was highly unlikely to have caused the reported dermatologic conditions. Widespread distribution of free samples of the new product appeared to be largely responsible for the frequency of anecdotal association of adverse reactions to use of the product. The diagnostic follow-up program is described.Le texte complet de cet article est disponible en PDF.