Contact allergy to decyl glucoside

Patch testing with glucosides: The North American Contact Dermatitis Group experience, 2009-2018

BACKGROUND

Alkyl glucosides are nonionic surfactants that are increasingly used in personal care products.

OBJECTIVE

To characterize positive patch test reactions to decyl glucoside (5% petrolatum, tested 2009-2018) and lauryl glucoside (3% petrolatum, tested 2017-2018).

METHODS

Retrospective analysis of patients tested by the North American Contact Dermatitis Group.

RESULTS

Of 24,097 patients patch tested to decyl and/or lauryl glucoside, 470 (2.0%) had positive reactions. Compared with glucoside-negative patients, glucoside-positive patients had higher odds of occupational skin disease (13.4% vs 10.1%; P = .0207), history of hay fever (38.5% vs 31.6%; P = .0014), atopic dermatitis (39.0% vs 28.6%; P < .0001), and/or asthma (21.8% vs 16.5%; P = .0023). Most glucoside reactions (83.9%) were currently relevant. The most common source was personal care products (63.0%), especially hair products (16.5%) and skin cleansers (15.2%). Of 4933 patients tested to decyl and lauryl glucoside, 134 (2.7%) were positive to 1 or both; 43.4% (43 of 99) of decyl-positive patients were also positive to lauryl glucoside and 55.1% (43/78) of lauryl glucoside patients were also positive to decyl glucoside.

LIMITATIONS

The cohort predominantly reflects a referral population, and follow-up after testing was not captured.

CONCLUSION

Glucoside positivity occurred in 2.0% of the tested patients. Reactions were often clinically relevant and linked to personal care products. Cross-reactivity was >40%.

Patch Testing with Decyl and Lauryl Glucoside: How Well Does One Screen for Contact Allergic Reactions to the Other?

BACKGROUND

Alkyl glucoside surfactants, present in many cosmetic products, can cause allergic contact dermatitis. Decyl glucoside has been part of the North American Contact Dermatitis Group standard allergen panel since 2009.

OBJECTIVES

This study aimed to identify rates and relevance of positive patch test reactions to decyl and lauryl glucosides and to determine how well one of these glucosides screens for contact allergic reactions to the other.

METHODS

A retrospective analysis was performed on 897 patients suspected of having a cosmetic-related dermatitis and patch tested with both decyl and lauryl glucosides between 2009 and 2016.

RESULTS

Forty-eight patients (5%) had positive reactions to decyl glucoside and/or lauryl glucoside. Among the alkyl glucoside-allergic patients, 65% had positive reactions to both decyl and lauryl glucosides. In 41% of cases, reactions were of definite or probable relevance. In approximately 55% of cases, reactions were of possible relevance.

CONCLUSIONS

Sixty-five percent of glucoside-allergic patients exhibited co-reactions to decyl and lauryl glucosides. Thus, neither glucoside is an adequate screen for allergy to the other. Given that these reactions are often relevant, clinicians should patch test with decyl, lauryl, and other alkyl glucosides in cases of suspected cosmetic allergy.

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.

New aspects in allergic contact dermatitis

PURPOSE OF REVIEW

To give selected new information on contact allergy and allergic contact dermatitis with focus on diagnostic procedures and pitfalls.

RECENT FINDINGS

Recent studies dealing with common contact allergens have improved our understanding of the relationship between positive patch tests and the clinical interpretation and consequences for the patient.

SUMMARY

Nickel allergy is still the most common contact allergy in Europe in spite of full implementation of the EU Nickel Directive in 2001. Contact allergens in cosmetics and topical drugs are another common cause of allergic contact dermatitis. The main culprits include fragrance chemicals, preservatives, and hair dyes. We are all more or less exposed to cosmetics and topical drugs on a daily basis. The labelling requirements given in the Cosmetics Directive is of great help in tracing the causative allergenic ingredients. Most of the components present in cosmetic products are also occurring in household and industrial products, often under other trade names. Patients with multiple contact allergies constitute a special problem because their quality of life is severely affected by the multitude of eliciting products in the environment. We still lack a good understanding of why these patients become so easily sensitized.