Discordant Patch Test Reactions to 2-Bromo-2-Nitro-Propane-1,3-Diol (Bronopol): A Multicenter Study From REIDAC

Abstract

2-Bromo-2-nitro-propane-1,3-diol (bronopol) is a formaldehyde releaser that was included as an emerging allergen needing to be evaluated in the European series in 2019, and as a candidate allergen for inclusion in the Spanish baseline series based on data from the Spanish Registry for Research in Dermatitis and Contact Allergy (REIDAC), in TRUE Test 0.25 mg/cm2 or 0.5% pet. in 2022. In a previous Spanish study, we perceived a frequency of sensitization to bronopol of 0.36% (15/4088) and we noted that the TRUE Test detected 13 of 15 overall reactions to bronopol. We found a current relevance of 6/13 in TRUE Test and none in petrolatum. However, one limitation of this work was that the data could not be directly compared because they came from different populations. The present study was then designed within REIDAC due to differences, with the aim of updating epidemological data regarding sensitizations to bronopol and evaluating discordant patch test reactions to bronopol.