Frequent exposure to water and
surfactants is considered to be the main cause of hand
eczema from wet work. Ethoxylated
surfactants are susceptible to oxidation and some of the oxidation products formed have proved to be contact sensitizers in guinea pigs. The question of human sensitization to oxidized
surfactants was addressed in a multicentre study in the Stockholm region. 528 consecutive
dermatitis patients were patch tested with widely used ethoxylated
surfactants in oxidized and non-oxidized form as well as certain identified oxidation compounds. 61 patients presented with mild, clearly
irritant reactions to some of the
surfactants tested. 18 patients showed not only
erythema but also oedema and/or papules and vesicles, using a morphologic descriptive system for reading the patch test reactions. These reactions occurred mostly to oxidized
surfactants and oxidation products. When retesting 9 of these 18 patients only an
allergic reaction to
acetaldehyde was confirmed. We conclude that oxidized ethoxylated
surfactants have increased
irritant potential compared to non-oxidized material. Our working hypothesis is that oxidized
surfactants of technical quality exert a lower risk of sensitization than do oxidized homologous pure
surfactants. Among the potential
allergens formed during autoxidation,
formaldehyde and
acetaldehyde must be considered as a source of unexpected exposure.