Allergic contact dermatitis from decyl glucoside in an antiseptic lotion

Impact of trends in new and emerging contact allergens

Allergic contact dermatitis represents a T cell-mediated, delayed-type hypersensitivity response to exogenous agents. While allergic contact dermatitis is one of the most common causes of skin disease encountered by dermatologists, emerging trends within the field are in constant flux, as influenced by ever-changing industry practices and evolving consumer behaviors. Although certain allergens continue to predominate, new chemicals are frequently being introduced, thus shifting the pattern of allergen exposure and sensitization. This review examines the impact of trends in new and emerging contact allergens, with particular attention to clinical contexts in which these agents may be encountered. In addition, we offer a working knowledge of these allergens’ characteristics, sources, and relevance, while outlining recommendations to accurately evaluate, diagnose, and provide appropriate counseling for these diseases.

The History of Surfactants and Review of Their Allergic and Irritant Properties

Surfactants, many of which are used as detergents, can be found in many common household items, such as shampoos, conditioners, soaps, and cosmetics. One should recognize the multitude of surfactants that are used in today's products to identify any potential allergic contact dermatitis (ACD) or irritant contact dermatitis (ICD). Given their abundance in everyday products, it is understandable that many cases of occupational contact dermatitis that arise can be attributed to surfactants. The products most connected with ACD are cocamidopropyl betaine, oleamidopropyl dimethylamine, decyl glucoside, 3-dimethylaminopropylamine, amidoamine, and cocamide diethanolamine. Similarly, the most common surfactant-related causes of ICD are sodium lauryl sulfate and benzalkonium chloride. It is important for dermatologists to identify the causes and differentiate between the two, to adjust treatments and products accordingly. Here, the most frequently used surfactants, as well as their correlation between ACD and ICD, will be reviewed.

Alkyl Glucosides

Alkyl glucosides are surfactants synthesized through the condensation of long-chain fatty alcohols and glucose, extracted from vegetal, renewable sources. Although available for more than 4 decades, they have been rediscovered in recent years because of their eco-friendly character. They are used in various leave-on and rinse-off cosmetics and are considered of low irritancy and allergenicity. However, since the early 2000s, cases of allergic contact dermatitis to this family of molecules have been repeatedly reported. Decyl glucoside was found to be a "hidden" allergen in the sunscreen ingredient Tinosorb M and is likely responsible for most allergic contact dermatitis reported to this compound. Members of the North American Contact Dermatitis Group have seen a steady increase of the rate of sensitization to decyl glucoside. Cross-reactions with other glucosides are common but not automatic; thus, patch testing multiple compounds is recommended.

Isobornyl acrylate: an impurity in alkyl glucosides

CONTEXT

Alkyl glucosides and alkyl poly-glucosides are widely used as wetting agents, surfactants and emulsifiers in several industrial and cosmetic products. They are known as well-tolerated and are usually added to the primary surfactants in order to reduce the irritating potential of the main foaming agents.

OBJECTIVE

Recently, some authors suggested that allergic contact dermatitis to alkyl glucosides might be more frequent than suspected. On the other hand, the chemical structures of glucosides do not show potentially allergenic chemical groups or strongly polarized structures. The aim of our study is to investigate alkyl glucosides carrying out a detailed chemical analysis on samples of raw materials to identify potentially allergenic impurities or by-products contained in commercial samples of alkyl glucosides.

MATERIALS AND METHODS

We chemically analyzed samples of cocoyl glucoside, decyl glucoside and lauryl glucoside by three different analytical methods, in order to identify any undesired or polluting substances.

RESULT

In each of the three samples, we detected the presence of isobornyl acrylate. Its approximate content in the tested samples is 500 ng/g of the product.

DISCUSSION

Isobornyl acrylate is not used in the synthesis of alkyl glucosides, but as a plasticizer in many plastic materials. It can be easily released to materials flowing over these surfaces when they have high extraction power, as glucosides.

CONCLUSION

Isobornyl acrylate may play a role as hidden allergen, in the form of an impurity collected during the industrial process, explaining some cases of allergic reaction to alkyl glucosides.

Safety Assessment of Decyl Glucoside and Other Alkyl Glucosides as Used in Cosmetics

The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of 19 alkyl glucosides as used in cosmetics and concluded that these ingredients are safe in the present practices of use and concentration when formulated to be nonirritating. Most of these ingredients function as surfactants in cosmetics, but some have additional functions as skin-conditioning agents, hair-conditioning agents, or emulsion stabilizers. The Panel reviewed the available animal and clinical data on these ingredients. Since glucoside hydrolases in human skin are likely to break down these ingredients to release their respective fatty acids and glucose, the Panel also reviewed CIR reports on the safety of fatty alcohols and were able to extrapolate data from those previous reports to support safety.