Background
A colorless chlorhexidine containing spray disinfectant is used very frequently in Switzerland to treat superficial wounds. A growing number of adverse cutaneous reactions related to the use of this disinfectant have been observed. It contains the following components: chlorexhidine digluconate 0.5%, benzoxonium 0.1%, lauryl-amine-oxide in small quantities.
Objectives
To investigate the allergens responsible for localized contact dermatitis in patients with suspected reaction after disinfectant use.
Patients/Materials/Methods (as appropriate)
Patch tests were carried out to explore the suspicion of contact allergy to Merfen® spray for a series of 7 patients with a clinical history compatible with this diagnosis.
Results
All patients presented acute eczema type reactions in the areas where they applied either Merfen spray alone or multiple products including Merfen spray. 5/7 patients showed positive reactions for Merfen® spray in Patch test or ROAT. No reaction was observed to chlorhexidine digluconate 0.5% from the commercial series or to a product of chlorhexidine in water 0.5% (Table 2). Furthermore 3 patients showed dose-dependent reactions for both benzoxonium chloride and lauryl-amine-oxide; while 2 patients showed reactions only for lauryl-amine-oxide.
Conclusions.
Two allergens non-commercially available are imputed for contact reactions to Merfen® spray: benzoxonium chloride and lauryl-amine-oxide. No sensitization to chlorhexidine which is the main component of Merfen® spray was observed in our series.

Identification of allergens responsible for contact allergy in a chlorhexidine-based disinfectant: benzoxonium chloride and lauryl-amine-oxide

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