Outbreak of contact sensitization to methylisothiazolinone: an analysis of French data from the REVIDAL-GERDA network

More than just methylisothiazolinone: Retrospective analysis of patients with isothiazolinone allergy in North America, 2017-2020

BACKGROUND

Isothiazolinones are a common cause of allergic contact dermatitis.

OBJECTIVE

To examine the prevalence of positive patch test reactions to isothiazolinones from 2017-2020 and characterize isothiazolinone-allergic (Is+) patients compared with isothiazolinone nonallergic (Is-) patients.

METHODS

Retrospective cross-sectional analysis of 9028 patients patch tested to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) 0.02% aqueous, MI 0.2% aqueous, benzisothiazolinone (BIT) 0.1% petrolatum, and/or octylisothiazolinone (OIT) 0.025% petrolatum. Prevalence, reaction strength, concurrent reactions, clinical relevance, and source of allergens were tabulated.

RESULTS

In total, 21.9% (1976/9028) of patients had a positive reaction to 1 or more isothiazolinones. Positivity to MI was 14.4% (1296/9012), MCI/MI was 10.0% (903/9017), BIT was 8.6% (777/9018), and OIT was 05% (49/9028). Compared with Is-, Is+ patients were more likely to have occupational skin disease (16.5% vs 10.3%, P <.001), primary hand dermatitis (30.2% vs 19.7%, P <.001), and be >40 years (73.1% vs 61.9%, P <.001). Positive patch test reactions to >1 isothiazolinone occurred in 44.1% (871/1976) of Is+ patients. Testing solely to MCI/MI would miss 47.3% (611/1292) of MI and 60.1% (466/776) of BIT allergic reactions.

LIMITATIONS

Retrospective cross-sectional study design and lack of follow-up data.

CONCLUSION

Sensitization to isothiazolinones is high and concurrent sensitization to multiple isothiazolinone allergens is common.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Contact Dermatitis Associated With Hair Care Products: A Retrospective Analysis of the North American Contact Dermatitis Group Data, 2001-2016

BACKGROUND

Hair care products (HCPs) may cause both allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD).

OBJECTIVES

The aims of the study were to determine the prevalence of HCP-associated ICD/ACD and to characterize relevant allergens.

METHODS

This study is a retrospective analysis of North American Contact Dermatitis Group (NACDG) patch test data, 2001-2016.

RESULTS

Of 38,775 patients tested, 3481 (9.0%) had positive patch test reactions associated with HCPs. The HCP-positive patients were significantly more likely to be female (79.9% vs 66.0%) and/or have primary sites of dermatitis on the face (32.0% vs 27.8%) or scalp (15.4% vs 2.2%) compared with the HCP-negative patients (P < 0.0001). Of 4908 HCP-associated positive patch test reactions, 86.9% (n = 4263) were due to allergens on the NACDG screening series; p-phenylenediamine (35.8%), methylisothiazolinone (9.7%), methylchloroisothiazolinone/methylisothiazolinone (8.7%), and cocamidopropyl betaine (5.9%) were the most frequent. Most reactions (87.7%, 3736/4263) were currently clinically relevant. The most common job associated with 366 occupationally related NACDG HCP-associated allergens was hairdresser/cosmetologist (71.9%). Two hundred eighty-two patients (0.7%) had ICD associated with HCPs. Shampoo/conditioners were the most frequent source of NACDG HCP-associated reactions (47.3%) and HCP-associated ICD (45.0%).

CONCLUSIONS

Of the HCP-positive patients, 18.5% had HCP reactions to allergens not on the NACDG screening series, underscoring the importance of patch testing to expanded series in patients suspected of HCP allergy.

Methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone contact allergy: A 24-year, single-center, retrospective cohort study from Turkey

BACKGROUND

Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI allergy caused a global epidemic during the period 2010 to 2015, reaching its peak in 2013/14.

OBJECTIVE

To investigate the characteristics of MCI/MI and MI allergy in Turkey over 24 years.

METHODS

A total of 2310 patients patch tested between 1996 and 2019 with MCI/MI 0.01% aq. or MCI/MI 0.02% aq., with or without MI 0.2% aq., were analyzed.

RESULTS

The overall prevalence of contact sensitization was 3.3% (n = 77) with a peak level of 16.4% in 2015. The prevalence gradually decreased thereafter, but was still high (6.5%) in 2019. Seventy-three patients had clinically relevant sensitizations. MI could detect clinically relevant sensitizations in all seven patients with a negative patch test reaction to MCI/MI 0.02%. Non-occupational allergic contact dermatitis (ACD) was most frequently seen, mainly in women, with hand/face eczema from rinse-off or leave-on cosmetics, such as wet wipes. Occupational ACD was mainly seen among men with airborne eczema from wall paints in house painters, or with hand eczema from hair gel/wax in men's barbers.

CONCLUSIONS

The prevalence of MCI/MI and MI sensitization in Turkey following the peak in 2015 is still high. This is probably due to the currently allowed level of 100 ppm for MI in rinse-off cosmetics. This needs to be urgently reduced.

Patch test in Chinese in Shanghai with cosmetic allergy to cosmetic series and products

BACKGROUND

There are increasing cosmetic adverse reactions in China, mostly cosmetic contact dermatitis, with the development of its cosmetics industry.

AIMS

To identify the allergens and cosmetics products responsible for cosmetic allergic contact dermatitis (CACD) in Shanghai.

METHODS

Five hundred and sixty patients, including 342 suspected CACD patients from dermatological clinic and 218 cosmetics consumers with an allergic history, were patch tested with a cosmetic series (C-1000 series). And 154 patients patched with possible culprit cosmetics.

RESULTS

Two hundred and forty-six subjects showed positive reaction to C-1000 series. Clinic patients had much higher positive rate than that of cosmetics consumers. Leading allergens were methylisothiazolinone (MI), methylisothiazolinone + methylchloro-isothiazolinone (MCI/MI), thimerosal, and the positive rates were significantly higher in patients than in cosmetic consumers (P < .001 for all). MCI/MI elicited positive patch test reactions in 73.5% of MI-positive patients. Of those patched with cosmetic products, 19 patients had 31 positive reactions, including 22 skin care products and 5 color decorating.

CONCLUSIONS

Preservatives, especially MI, MCI/MI, and thimerosal, were the most common cosmetic allergens, and skin care products occupied the most allergic reaction of CACD. Patch testing is highly recommended for suspected CACD patients. Future comparative investigation with large sample size should benefit cosmetovigilance surveillance.

Amended Safety Assessment of Methylisothiazolinone as Used in Cosmetics

The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of methylisothiazolinone (MI), which functions as a preservative. The Panel reviewed relevant animal and human data provided in this safety assessment and in a previously published safety assessment of MI and concluded that MI is safe for use in rinse-off cosmetic products at concentrations up to 100 ppm and safe in leave-on cosmetic products when they are formulated to be nonsensitizing, which may be determined based on a quantitative risk assessment.

Isothiazolinone in Residential Interior Wall Paint: A High-Performance Liquid Chromatographic-Mass Spectrometry Analysis

BACKGROUND

There is limited information regarding isothiazolinone content in residential wall paints in the United States.

OBJECTIVE

The aim of this study was to evaluate the prevalence of 5 isothiazolinones-methylisothiazolinone (MI), methylchloroisothiazolinone, benzisothiazolinone (BIT), butyl BIT, and octylisothiazolinone-in US residential wall paints.

METHODS

Forty-seven paints were obtained from retailers in Minneapolis/St Paul, Minnesota. Paint samples were assessed for the presence of the 5 isothiazolinones using high-performance liquid chromatographic-mass spectrometry.

RESULTS

At least 1 isothiazolinone was detected in all 47 paints. However, no paint contained butyl BIT, and only 1 paint had octylisothiazolinone. The MI and BIT were found in 96% and 94% of the paints, respectively. Methylisothiazolinone ranged in concentration from 17 to 358 ppm, whereas BIT varied from 29 to 1111 ppm. Methylchloroisothiazolinone was found solely in oil-based paints. Isothiazolinones were declared in 15% of Safety Data Sheets but did not correlate with high-performance liquid chromatographic-mass spectrometry. One "preservative-free" paint had BIT at 71.5 ppm. Paint sheen was not statistically associated with BIT or MI concentrations. Unpigmented paints and paints with volatile organic compound claims had significantly lower concentrations of MI, but not BIT.

CONCLUSIONS

All paints contained at least 1 isothiazolinone. Methylisothiazolinone and BIT were the most common. Safety Data Sheets are insufficient for ascertaining isothiazolinone content in US paints.

Isothiazolinone derivatives and allergic contact dermatitis: a review and update

Allergic contact dermatitis (ACD) from isothiazolinones has frequently been described in the literature. Following an epidemic of sensitization to methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) in the 1980s, and more recently to MI, the Scientific Committee on Consumer Safety of the European Commission banned their use in leave-on products, while restricting that in rinse-off cosmetics. Despite a decreasing prevalence of ACD from MCI/MI and MI, cases caused by occupational exposure and non-cosmetic isothiazolinone sources are on the rise. Moreover, sensitization to newer and lesser known isothiazolinones has been reported. This paper reviews the epidemiology of contact allergy to different isothiazolinones, clinical presentation of isothiazolinone-induced ACD, most relevant sensitization sources and potential cross-reactions between isothiazolinone derivatives. It also provides an update on recent legislative measures.

Is a specific eyelid patch test series useful? Results of a French prospective study

BACKGROUND

Eyelids are frequent sites of contact dermatitis. No prospective study focused on eyelid allergic contact dermatitis (EACD) has yet been published, and this topic has never been studied in French patients.

OBJECTIVES

To prospectively evaluate the usefulness of an eyelid series in French patients patch tested because of EACD, and to describe these patients.

METHODS

We prospectively analysed standardized data for all patients referred to our departments between September 2014 and August 2016 for patch testing for suspected EACD as the main reason. All patients were patch tested with an eyelid series, the European baseline series (EBS), the French additional series, and their personal products. Patch testing with additional series and repeated open application tests (ROATs) or open tests were performed if necessary. A standardized assessment of the relevance was used, and the analysis of the results was focused on patients having positive test results with a current certain relevance.

RESULTS

Two-hundred and sixty-four patients (238 women and 26 men) were included. Three-hundred and twenty-two tests gave positive results in 167 patients, 84 of whom had currently relevant reactions: 56 had currently relevant positive test reactions to the EBS, 16 had currently relevant positive test reactions to their personal products, 8 had currently relevant positive test reactions to the French additional series, and 4 had currently relevant positive test reactions to the eyelid series. Sixty-seven per cent of all relevant cases were related to cosmetic products. The most frequent allergens with current relevance were methylisothiazolinone (10.2%), fragrance mix I (3%), nickel (2.7%), hydroxyperoxides of linalool (2.7%) and limonene (2.3%), and Myroxylon pereirae (2.3%). Current atopic dermatitis was found in 9.5% of patients. The duration of dermatitis was shorter (23.2 vs 34.2 months; P = .035) in patients with currently relevant test reactions. The percentage of currently relevant tests remained the same when atopic patients or dermatitis localized only on the eyelids were taken into account.

CONCLUSION

In French patients, testing for EACD with the extended baseline series and personal products, also including ROATs and use tests, appears to be adequate, considering the currently relevant positive test reactions. The regular addition of an eyelid series does not seem to be necessary.

Microbial Stability of Pharmaceutical and Cosmetic Products

This review gives a brief overview about microbial contamination in pharmaceutical products. We discuss the distribution and potential sources of microorganisms in different areas, ranging from manufacturing sites, pharmacy stores, hospitals, to the post-market phase. We also discuss the factors that affect microbial contamination in popular dosage forms (e.g., tablets, sterile products, cosmetics). When these products are contaminated, the microorganisms can cause changes. The effects range from mild changes (e.g., discoloration, texture alteration) to severe effects (e.g., changes in activities, toxicity). The most common method for countering microbial contamination is the use of preservatives. We review some frequently used preservatives, and we describe the mechanisms by which microorganisms develop resistance to these preservatives. Finally, because preservatives are inherently toxic, we review the efforts of researchers to utilize water activity and other non-preservative approaches to combat microbial contamination.

Skin sensitization

Skin sensitization associated with allergic contact dermatitis is a common health problem and is an important consideration for toxicologists in safety assessment. Historically, in vivo predictive tests have been used with good success to identify substances that have the potential to induce skin sensitization, and these tests formed the basis of safety evaluation. These original tests are now being replaced gradually either by in vitro assays or by further refinements of in vivo methods such as the local lymph node assay. Human data have also been available to inform classification decisions for some substances and have been used by risk managers to introduce measures for exposure reduction. However, humans encounter hazards in the context of exposure rather than in the form of intrinsic hazards per se, and so in this article, we have examined critically the extent to which human data have been used to refine classification decisions and safety evaluations. We have also evaluated information on the burden of human allergic skin disease and used this to address the question of whether, and to what extent, the identification and evaluation of skin sensitization hazards has led to an improvement of public and/or occupational health.

[What's new in clinical dermatology?]

Dermatoses have been better characterized as hypochromic vitiligo in subjects with dark skin or the acquired racquet nails associated with hyperparathyroidism. The innate immunity has a central role in the new classification of auto inflammatory diseases, neutrophilic dermatoses, neutrophilic urticaria or pseudo-neutrophilic urticaria. Comorbidities have been studied e.g. cardiovascular co morbidities for psoriasis, IBD associated with hidradenitis suppurativa or neurological disorders associated with pemphigoid. Bullous pemphigoid could be renamed as cutaneous pemphigoid, it can be induced by drugs especially gliptins. Genetic predispositions are analyzed in auto inflammatory diseases, psoriasis (HLA), drug eruptions (HLA or cytokines). Telaprevir often induces rashes, which can be severe but other treatments against hepatitis C as interferon can also induce debilitating rashes, some eligible for drug tolerance induction. European guidelines for the definition, classification, diagnosis of chronic spontaneous urticaria have been published. Severe cutaneous adverse drug reactions may be associated with severe systemic symptoms such as organ involvement in AGEP or the occurrence of a shock in DRESS. Allover Europe, there is now an epidemic of contact allergies to methylisothiazolinone (MIT), contained in cosmetics, wet wipes but also in paints. MIT should be tested at 2.000 ppm in water, included in the standard series for patch tests. Its role has to be evoked in any case localized on the face or hand, airborne or generalized eczema. Among infectious diseases, skin manifestations due to Parvovirus have been specified, a febrile rash can be related to dengue infection or to Zika virus.