2017 Volume 11 Issue 1 Pages 55-63
A 60-year-old woman had a history of contact dermatitis to vinyl chloride gloves. She wore a newly bought brassiere for 2 consecutive days without exhibiting any symptoms. On the third day, the brassiere was washed, hung out to dry, and worn again. She then developed edematous erythema on her back consistent with the brassiere straps. Patch test with the brassiere strap was positive. Componential analysis detected the presence of the trans isomer of Di (2-ethylhexyl) fumarate (DEHF) and the cis isomer of Di (2-ethylhexyl) maleate (DEHM) in the brassiere. DEHF was negative on patch test but DEHM tested positive. We irradiated DEHF in vitro with UV and called the resulting compound DEHF-UV. DEHF-UV was positive on PT ; DEHF was transformed to DEHM by irradiation with UV, and trans-cis conversion was verified with spectroscopic methods. We concluded that DEHM was the allergen in this case. Her medical history of contact dermatitis to vinyl chloride gloves was thought to be caused by mono (2-ethylhexyl) maleate (MEHM) . It is assumed that she was already sensitive to MEHM. MEHM and DEHM have common structures. MEHM was not found in the brassiere, but we also did a patch test with MEHM and it was positive. We then performed patch tests with several chemicals of similar structure ; it was found that the combination of a 2-ethylhexyl group, a cis-double bond and a carboxyl group are necessary for the epitope.
