Non-fragrance allergens in specific cosmetic products

Patch Testing to Mentha piperita (Peppermint) Oil: The North American Contact Dermatitis Group Experience (2009-2020)

Background: Mentha piperita (MP; peppermint) oil has many commercial uses. Objective: To characterize the epidemiology of contact allergy to MP oil 2% petrolatum. Methods: Retrospective analysis of North American Contact Dermatitis Group data (2009-2020). Results: Of 28,128 patients tested to MP, 161 (0.6%) had an allergic reaction. Most allergic patients were female (77.0%) and/or over 40 years of age (71.4%). The most common anatomical sites of dermatitis included face (31.7%; of these, one-third specified lips), hands (17.4%), and scattered/generalized (18.6%). Nearly one-third (30.4%) of reactions were strong (++)/extreme (+++), and 80.1% were considered currently relevant. Common sources included oral hygiene preparations, foods, and lip products. Co-reaction with at least 1 of the other 19 fragrance/plant-related screening test preparations occurred in 82.6% (133/161) of MP-allergic patients, most commonly Cananga odorata oil (42.9%), fragrance mix I (41.0%), hydroperoxides of linalool (35.7%), Compositae mix (35.4%), Jasminum officinale oil (31.9%), Myroxylon pereirae (31.7%), and propolis (28.1%). Co-reaction with at least 1 of the 3 most commonly used fragrance screening allergens (fragrance mix I, fragrance mix II, and/or Myroxylon pereirae) was 59.6%. Conclusions: Twelve-year prevalence of MP allergy was 0.6%. Approximately 40% of cases would have been missed if only fragrance screening allergens were tested.

Responsive photonic hydrogel for colorimetric detection of formaldehyde

Formaldehyde (FA) can damage DNA, cause liver and kidney dysfunction, and ultimately lead to malignant tumors. Therefore, it is essential to develop a method that can conveniently detect FA with high detection sensitivity. Here, a responsive photonic hydrogel was prepared by embedding three-dimensional photonic crystal (PC) into amino-functionalized hydrogel to construct a colorimetric sensing film for FA. The amino groups on the polymer chains of the photonic hydrogel reacts with FA to increase the crosslinking density of the hydrogel, resulting in its volume shrinkage and a decrease in microsphere spacing of the PC. That causes the reflectance spectra blue-shift of more than 160 nm and color change from red to cyan for the optimized photonic hydrogel, achieving the sensitive, selective and colorimetric detection of FA. The constructed photonic hydrogel shows good accuracy and reliability for practical determination of FA in air and aquatic products, providing a new strategy for designing other target analytes responsive photonic hydrogels.

Patch Testing With Benzophenone-3 and -4: The North American Contact Dermatitis Group Experience, 2013-2020

Background: Benzophenone (BZP)-3 and BZP-4 are ultraviolet (UV) absorbers used in sunscreens and personal care products (PCPs) and may cause allergic contact dermatitis. Objective: To characterize positive patch test reactions to BZP-3 (10% in petrolatum [pet]) and BZP-4 (2% pet) in a screening allergen series. Methods: Retrospective analysis of patients tested to BZP-3 and BZP-4 was conducted by the North American Contact Dermatitis Group from 2013 to 2020. Results: Of 19,618 patients patch tested to BZP-3 and BZP-4, 103 (0.5%) and 323 (1.6%) had positive reactions, respectively: 413 (2.1%) reacted to at least 1 BZP (BZP-positive patient). As compared with BZP-negative patients, BZP-positive patients were significantly more likely to have a history of hay fever (39.3% vs 33.4%, P = 0.0134), history of atopic dermatitis (39.8% vs 30.7%, P = 0.0001), and facial involvement (37.4% vs 32.2%, P = 0.0272). Most reactions were currently clinically relevant (BZP-3: 90.4%; BZP-4: 65.8%). Common identified sources included PCPs and sunscreens. Coreactivity between BZP-3 and BZP-4 was low: 13.5% (14/104) of BZP-3-positive patients were allergic to BZP-4 and 4.3% (14/322) of BZP-4-positive patients were allergic to BZP-3. Conclusions: Eight-year prevalence of BZP positivity was 2.1%. Reactions were frequently clinically relevant and linked to PCPs and sunscreens.

A Review of Moisturizers; History, Preparation, Characterization and Applications

Moisturizers are one of the most widely used preparations in cosmetics and have been extensively used to soften the skin for consumers. Moisturizers work effectively in combating dry skin which may cause pain, tightness, itch, stinging, and/or tingling. The aim of this review is to evaluate published studies on the history, ingredients, preparation processes, characteristics, uses, and applications of moisturizers. Moisturizers bridge the gap between medicine and consumer goods by being used to make the skin more beautiful and healthy. In the future, in moisturizer therapy, the capacity to adapt specific agents to specific dermatological demands will be crucial. Cosmetically, moisturizers make the skin smooth by the mechanism of increasing the water content in the stratum corneum, hence exerting its most vital action, which is moisturizing action and maintaining a normal skin pH.

Preservative Contact Hypersensitivity among Adult Atopic Dermatitis Patients

Atopic dermatitis (AD) is a chronic inflammatory disease characterised by an impaired skin barrier. The prolonged use of topical preparations containing medications, emollients, fragrances and preservatives may increase the risk of contact hypersensitivity (CHS). In the Allergy Outpatient Unit of the Department of Dermatology, Venereology and Dermatooncology of Semmelweis University, 5790 adult patients were patch tested between 2007–2021 with the European Environmental Baseline Series according to international standards. Among all the tested adult patients, 723 had preservative CHS (PCHS) and 639 had AD. Among the 723 PCHS patients, 68 (9.4%) had AD; the female to male ratio was 3:1 in this group. Out of 639 AD patients, 68 had PCHS (10.6%). In the AD-PCHS group, 83.8% had CHS to methylisothiazolinone (MI) (tested from 2014), 36.8% to Kathon CG^®, 16.2% to methyldibromo-glutaronitrile, 11.8% to paraben, 7.4% to formaldehyde, 4.4% to para-tert-butylphenol-formaldehyde resin and 1.5% to Quaternium-15. The most common concomitant PCHS combination was Kathon CG^® + MI. Most patients (32.4%) belonged to the age group of 21–30, and skin symptoms affected mostly the limbs and face. The most common other concomitant allergens were nickel, lanolin alcohol and balsam of Peru. Preservatives (especially MI and Kathon CG^®) are important contact allergens in adult AD, mostly among young women. The rate of AD in the PCHS group and the rate of PCHS in the AD group is remarkable; thus, the role of PCHS should be highlighted in the topical therapy and in the prevention of possible AD exacerbations.

Identification of Novel Inhibitors of Escherichia coli DNA Ligase (LigA)

Present in all organisms, DNA ligases catalyse the formation of a phosphodiester bond between a 3' hydroxyl and a 5' phosphate, a reaction that is essential for maintaining genome integrity during replication and repair. Eubacterial DNA ligases use NAD⁺ as a cofactor and possess low sequence and structural homology relative to eukaryotic DNA ligases which use ATP as a cofactor. These key differences enable specific targeting of bacterial DNA ligases as an antibacterial strategy. In this study, four small molecule accessible sites within functionally important regions of Escherichia coli ligase (EC-LigA) were identified using in silico methods. Molecular docking was then used to screen for small molecules predicted to bind to these sites. Eight candidate inhibitors were then screened for inhibitory activity in an in vitro ligase assay. Five of these (geneticin, chlorhexidine, glutathione (reduced), imidazolidinyl urea and 2-(aminomethyl)imidazole) showed dose-dependent inhibition of EC-LigA with half maximal inhibitory concentrations (IC₅₀) in the micromolar to millimolar range (11-2600 µM). Two (geneticin and chlorhexidine) were predicted to bind to a region of EC-LigA that has not been directly investigated previously, raising the possibility that there may be amino acids within this region that are important for EC-LigA activity or that the function of essential residues proximal to this region are impacted by inhibitor interactions with this region. We anticipate that the identified small molecule binding sites and inhibitors could be pursued as part of an antibacterial strategy targeting bacterial DNA ligases.

Two decades of p-phenylenediamine and toluene-2,5-diamine patch testing - focus on co-sensitizations in the European baseline series and cross-reactions with chemically related substances

BACKGROUND

Cross-reactions and co-sensitizations are of great importance in understanding contact allergy and exposure sources.

OBJECTIVES

To investigate common cross-reactions and co-sensitizations in p-phenylenediamine (PPD)-sensitized and toluene-2,5-diamine (TDA)-sensitized individuals.

METHODS

From our patch test population, 8036 patients patch tested with the European baseline series were extracted. Readings had to be performed at least on day 3 according to ICDRG guidelines.

RESULTS

Two hundred and fifty-one patients were sensitized to PPD and/or TDA; 231 patients were sensitized to PPD, and 109 to TDA. Significant differences were observed regarding the strengths of patch test reactions to PPD and number of cross-reactions. For TDA, a difference was found between all reaction strengths, except between + and ++ strengths. PPD-sensitized individuals were more likely to be sensitized to carba mix, cobalt chloride, colophonium, p-tert-butyl phenolformaldehyde resin, paraben mix, and methylisothiazolinone. TDA-sensitized individuals were more often sensitized to carba mix.

CONCLUSIONS

Cross-reactivity was commonly found among individuals sensitized to PPD or TDA, and was strongly related to the strength of the patch test reaction. Regarding co-sensitizations, a frequently appearing or common exposure source could not be determined. However, modification of the allergen by, for example, the skin microbiota may have caused the formation of molecules that are, for the human immune system, indistinguishable from PPD.

Evaluation of Functionality and Biological Responses of Mytilus galloprovincialis after Exposure to Quaternium-15 (Methenamine 3-Chloroallylochloride)

Although the irritant effects of quaternium-15 have been established, little is known about the toxicological consequences induced by this xenobiotic on aquatic invertebrates. The present article reports toxicological, histological and physiological effects of quaternium-15 following the exposure of Mytilus galloprovincialis for 18 days at three different concentrations (0.1, 1.0 and 2.0 mg/L). The results demonstrate that at higher concentrations histological damages to M. galloprovincialis gills occur, like melanosis, light exfoliations, increase of mucus production and infiltrative inflammation. In addition digestive gland cells of M. galloprovincialis, were not able to perform the regulation volume decrease (RVD) owing to osmotic stress following the exposure to the preservative. Overall, this first study on quaternium-15 highlights that it can jeopardize both the morphology and vital physiological processes in marine invertebrates, depending on the duration of exposure and the concentration of the preservative, indicating that further studies are necessary to increase our knowledge about the effects of this substance, commonly added to our products of daily use.

Cosmetic preservative labelling on the Thai market

BACKGROUND

Preservatives are added to cosmetics and other consumer products to prevent microbial growth and product degradation. Many cosmetic preservatives are skin sensitizers and frequent causes of contact dermatitis. The use of preservatives may vary by country and/or region, according to legislation, and may be reflected in differences in the prevalence rates of preservative allergy worldwide.

OBJECTIVE

To examine the type and frequency of preservative use in cosmetics sold in Thai markets in metropolitan Bangkok, Thailand.

METHODS

Preservatives contained in 1000 different cosmetics sold in Thai markets were documented and analysed, based on the labelling of ingredients.

RESULTS

Most of the cosmetic and skincare products sold in Thai markets were international brands, with only a small proportion of cosmetic products being produced in Thailand. International brand cosmetics were more likely to contain non-formaldehyde-releasing preservatives than domestically produced brands. Isothiazolinone-based preservatives, which are responsible for the current increase in the prevalence of contact allergy, were found at a significant frequency in domestically produced, leave-on cosmetic products.

CONCLUSION

Preservatives in cosmetics were significantly different according to source of production and type of cosmetics.

A Workflow to Investigate Exposure and Pharmacokinetic Influences on High-Throughput in Vitro Chemical Screening Based on Adverse Outcome Pathways

BACKGROUND

Adverse outcome pathways (AOPs) link adverse effects in individuals or populations to a molecular initiating event (MIE) that can be quantified using in vitro methods. Practical application of AOPs in chemical-specific risk assessment requires incorporation of knowledge on exposure, along with absorption, distribution, metabolism, and excretion (ADME) properties of chemicals.

OBJECTIVES

We developed a conceptual workflow to examine exposure and ADME properties in relation to an MIE. The utility of this workflow was evaluated using a previously established AOP, acetylcholinesterase (AChE) inhibition.

METHODS

Thirty chemicals found to inhibit human AChE in the ToxCast™ assay were examined with respect to their exposure, absorption potential, and ability to cross the blood-brain barrier (BBB). Structures of active chemicals were compared against structures of 1,029 inactive chemicals to detect possible parent compounds that might have active metabolites.

RESULTS

Application of the workflow screened 10 "low-priority" chemicals of 30 active chemicals. Fifty-two of the 1,029 inactive chemicals exhibited a similarity threshold of ≥ 75% with their nearest active neighbors. Of these 52 compounds, 30 were excluded due to poor absorption or distribution. The remaining 22 compounds may inhibit AChE in vivo either directly or as a result of metabolic activation.

CONCLUSIONS

The incorporation of exposure and ADME properties into the conceptual workflow eliminated 10 "low-priority" chemicals that may otherwise have undergone additional, resource-consuming analyses. Our workflow also increased confidence in interpretation of in vitro results by identifying possible "false negatives."

CITATION

Phillips MB, Leonard JA, Grulke CM, Chang DT, Edwards SW, Brooks R, Goldsmith MR, El-Masri H, Tan YM. 2016. A workflow to investigate exposure and pharmacokinetic influences on high-throughput in vitro chemical screening based on adverse outcome pathways. Environ Health Perspect 124:53-60; http://dx.doi.org/10.1289/ehp.1409450.

Self-reported Lupus flare: Association with everyday home and personal product exposure

BACKGROUND

The number of chemicals in household products has driven concern about potential adverse health through their use. Most research concentrates on product chemicals with reproductive and carcinogenic consequences, however some evidence exists that immune effects can lead to exacerbation of autoimmune illnesses such as lupus (SLE).

OBJECTIVES

This paper examines household and personal product exposure patterns in a pilot case/control study of female Australians. We also examined associations between common product exposure and SLE symptom exacerbation over a year period.

METHODS

We enrolled 41 control and 80 SLE participants aged 18-80 years. Qualitative techniques of structured interview and thematic analysis retrospectively explored patterns of product use, and flare history data of SLE participants. Negative binomial regression models explored associations between self-reported flare (SRF) days and exposure to 34 common home product groups.

RESULTS

Mean product counts did not differ between participant groups (mean 33.1: SD 11.8), or flare groups (flare mean 32.6:SD 12, no-flare 31.8:SD 6.6). Products used for personal hygiene and general house cleaning were most frequently used.Significant association with increased SRF day relative risk (IRR) was seen for bath oil use (IRR 1.008, CI 1.00-1.02). Paradoxical "protective" effects, (reduced SRF days) were found for cleansing beauty (IRR 0.999, CI 0.998-0.999), make-up (IRR 0.998, CI 0.997-0.999); adhesives (IRR 0.994, CI 0.991-0.997) and paint (IRR 0.99, CI 0.986-0.995).

CONCLUSIONS

Everyday product exposures can impact on symptom exacerbation in SLE. Some offering protection and others increased health risk. Identifying environmental associations offer the possibility of life-style interventions to reduce illness impact.

Propolis: a review of properties, applications, chemical composition, contact allergy, and other adverse effects

Propolis (bee glue) is the resinous substance that bees collect from living plants for the construction and adaptation of their nests. It has antibacterial, antifungal, and antiviral properties and may have a wide range of other beneficial biological activities. Propolis is available as a dietary supplement, in products for the protection of health and prevention of diseases, in biopharmaceuticals, and as a constituent of (bio)cosmetics. In this article, the following aspects of propolis are reviewed: the nature and chemical composition, its biological properties and applications, contact allergy and allergic contact dermatitis (sensitizing potential, products causing contact allergy, clinical picture, frequency of sensitization, coreactivity and cross-reactivity, the allergens in propolis), and other adverse effects.

Contact dermatitis in a child from methlychloroisothiazolinone and methylisothiazolinone in moist wipes

Contact allergic reactions to methlychloroisothiazolinone/methylisothiazolinone also widely known as Kathon CG have been reported extensively reported. It is one of the most commonly used preservatives in rinse-off products, cosmetics, and others. Herein, a case of a 50-year-old girl is presented with chronic dermatitis in the anogenital area. The patient was patch tested and had positive reaction to Kathon CG. The detailed history taking revealed that the allergen was present in the moist cleaning wipes used instead of dry toilet paper. The presented case serves as a basis for a appraisal of the use of this preservative in wet wipes. In addition, the duration of the patch test protocol in children has also been discussed.

Solid lipid nanoparticles as effective reservoir systems for long-term preservation of multidose formulations

Cosmetic multidose preparations, as well as pharmaceutical ones, are at risk of contamination by microorganisms, due to their high water content. Besides the risk of contamination during manufacturing, multidose cosmetic preparations may be contaminated by consumers during their use. In this paper, the results of the utilization of nanoparticles as reservoir systems of parabens, the most used class of preservatives, were reported. Two different systems, solid lipid nanoparticles (SLN) made of pure precirol and nanostructured lipid carriers (NLC) made of precirol and almond oil, containing three parabens as single molecules or as a mixture, were prepared and tested. All the systems were characterized for size, polydispersion index, zeta potential and encapsulation efficiency. Release experiments, carried out in steady state and sink conditions, allowed to evidence that both SLN and NLC were able to act as reservoir systems. The antimicrobial activity of the systems was tested against Candida albicans ATCC 10231 with repeat insult tests. The results of the release experiments and the antimicrobial tests showed very low water concentration of parabens still maintaining their antimicrobial activity.