Ethylene oxide as an occupational contact allergen – an underestimated problem?

Background: Ethylene oxide (EtO) is a volatile epoxy compound which is used to sterilize medical devices. EtO may cause irritant contact dermatitis, but only few cases of allergic contact dermatitis have been reported yet. Objectives: About 20 employees of a department for surgery developed eczematous skin reactions at the contact areas to wrist bands of surgical gowns which had been sterilized with EtO. Patch tests were performed to exclude contact allergy. Methods: Due to the volatility of EtO, patch tests were done with epichlorohydrin (0.1% pet., 1% pet.) which is an epoxy compound chemically related to EtO. Results: 7/8 patients and 4 healthy control persons showed non-allergic irritant reactions to 1.0% epichlorohydrin. 1.0% epichlorohydrin may have induced an iatrogenic sensitization in one of the control persons. None of the control persons reacted to 0.1% epichlorohydrin. Allergic contact dermatitis to EtO and a cross sensitization to epichlorohydrin was diagnosed in a nurse who showed an allergic crescendo patch test reaction to 0.1% epichlorohydrin. Conclusions: EtO can act as an occupational contact allergen in health personnel, a problem that may have been underestimated in the past due to methodological difficulties in patch testing. When allergic contact dermatitis to EtO is suspected, a patch test to 0.1% epichlorohydrin should be performed.