Patch testing with alkyl glucosides: Concomitant reactions are common but not ubiquitous.

Background: Alkyl glucosides contitute a family of mild surfactants that are increasingly being used in a wide range of cosmetics and household products. Contact allergy to alkyl glucosides may be more frequent than previously suspected, especially in atopic patients.

Objectives: To investigate the frequency of contact allergy to alkyl glucosides, and to identify concomitant reactivity.

Method: We retrospectively reviewed all cases of suspected allergic contact dermatitis (ACD) in which patients were patch tested with either a cosmetic series that includes five alkyl glucosides (decyl glucoside, lauryl glucoside, coco glucoside, cetearyl glucoside, and caprylyl/capryl glucoside) or a specific alkyl glucoside series from November 2013 to April 2017 in two UK centres.

Results: A total of 5775 patients were patch tested across the two centres. Twenty-nine (1.04%) of the 2796 patients tested with the cosmetic/alkyl glucoside series had a positive patch test reaction to at least one of the alkyl glucosides. Twenty-three (79.3%) patients were sensitized to multiple alkyl glucosides; 21 patients (72.4%) were female. The mean age was 43.5 years. Twelve patients (41.4%) had a background of atopic dermatitis.

Conclusions: The prevalence of alkyl glucoside-induced ACD is relatively high, and there are frequent concomitant reactions between different alkyl glucosides. We recommend the inclusion of alkyl glucosides in all cosmetic series.