Allergic contact dermatitis due to nitrile rubber gloves: Ethyl isothiocyanate and butyl isothiocyanate as possible causative chemicals

Abstract

Background: The causative chemicals responsible for nitrile rubber glove-induced allergic contact dermatitis have not been fully elucidated. Subject: This case involved a 36-year-old female, who developed an erythematous rash on her hands after one and a half months of wearing nitrile rubber gloves at her workplace. Methods: Patch tests were performed using the gloves as is, and the Japanese standard allergen 2008 and their components. The gloves were chemically analyzed and several detected substances were subjected to further patch testing. Results: The patient exhibited positive patch test reactions to nitrile rubber gloves as is, as well as to the dithio-carbamate mix and thiuram mix in the Japanese standard allergen 2008. Further patch testing revealed positive reactions to zinc diethyldithiocarbamate (ZDEC) and tetraethylthiuram disulfide (TETD) and weak positive reactions to zinc dimethyldithiocarbamate (ZDMC) and tetramethylthiuram monosulfide (TMTM). Chemical analysis revealed that ethyl isothiocyanate (EITC) and butyl isothiocyanate (BITC), which might have been produced from dithiocarbamate-type accelerators (DTCs) or thiuram-type accelerators (thiurams) during the vulcanization process, were present in the nitrile rubber gloves the patient used at her workplace, as was ZDBC. No other DTCs or thiurams were detected. Patch testing of the detected materials produced positive reactions to EITC and BITC, but not to ZDBC. Conclusion: We diagnosed the patient with allergic contact dermatitis due to the EITC and BITC present in nitrile rubber gloves, and considered that alkyl isothiocyanate might also have played a causative role. We propose that nitrile rubber gloves should be produced without using vulcanization accelerators.