Methylisothiazolinone Contact Allergy Research Articles

North American Contact Dermatitis Group Patch Test Results: 2019-2020.

Background: Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD). Objective: This study documents the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2019, to December 31, 2020. Methods: At 13 centers in North America, patients were tested in a standardized manner with a screening series of 80 allergens, and, as indicated, supplemental allergens. Results: Overall, 4121 patients were tested; 2871 (69.7%) had at least 1 positive/allergic patch test reaction and 2095 patients (51.2%) had a primary diagnosis of ACD. The most commonly positive allergens were nickel (18.2%), methylisothiazolinone (MI) (13.8%), fragrance mix (FM) I (12.8%), hydroperoxides of linalool (HPL) (11.1%), and benzisothiazolinone (BIT) (10.4%). Compared with that of 2017-2018, prevalence of top 20 allergens statistically increased for FM I, HPL, BIT, propolis, and hydroperoxides of limonene (3.5%). For the first time, MI positivity did not increase between reporting periods. Approximately one-fifth of patients (20.3%) had ≥1 clinically relevant reaction(s) to allergens/substances not on the NACDG series. Conclusions: The epidemic of MI contact allergy in North America may have reached a plateau. Patch testing using a robust screening series, and supplemental allergens as indicated, is necessary for comprehensive evaluation of ACD.

The epidemic of contact allergy to methylisothiazolinone-An analysis of Danish consecutive patients patch tested between 2005 and 2019.

In 2005, methylisothiazolinone (MI) was allowed as a stand-alone preservative in cosmetics. This resulted in an epidemic of allergic contact dermatitis to MI, mainly affecting women exposed to leave-on cosmetics. Consequently, a regulation of Annex V in the European Union in 2017 banned the use of MI in leave-on cosmetics and reduced the allowed concentration in rinse-off products. To analyze the temporal trends in contact allergy to MI in Danish patients in relation to key events including European regulations over time. A retrospective study of consecutive patients patch tested with methylisothiazolinone from 2005 to 2019. Demographics and clinical characteristics in terms of MOAHLFA (male, occupational, atopic dermatitis, hand dermatitis, leg dermatitis, facial dermatitis and age >40 years), sources of exposure, and clinical relevance were analyzed in relation to key historical events. Three hundred eighty of 12 494 patients (3.0%, 95CI: 2.7-3.4%) tested from 2005 to 2019 were sensitized to MI. An increasing trend in the prevalence of MI contact allergy from 2005 to 2019 (P < .01) was observed, although a decline in the absolute number of patch-test positive patients was seen from 2013 and onward. A reduction in leave-on cosmetics as a source of exposure was observed following the legislative ban in 2017, from 24.8% from in 2010 to 2013 to 6.2% in 2017 to 2019 (P < .01). The epidemic of MI contact allergy is declining in absolute terms, although the prevalence in the patch-tested population has not returned to its pre-epidemic levels. The legislative regulation of MI in 2017 has been effective in terms of leave-on cosmetics as a source of exposure in MI allergic patients. The process of post-marketing risk assessment of contact allergens in the European Union needs improvement.

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

Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI allergy caused a global epidemic during the period 2010 to 2015, reaching its peak in 2013/14. To investigate the characteristics of MCI/MI and MI allergy in Turkey over 24 years. 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. 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. 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.

The epidemic of methylisothiazolinone contact allergy in Europe: follow-up on changing exposures.

Methylisothiazolinone (MI) has caused an unprecedented epidemic of contact allergy in Europe and elsewhere. Subsequently, regulatory action has been taken, at least in Europe, aiming at reducing risk of MI sensitization. To follow-up on the prevalence of contact allergy to MI in consecutively patch tested patients and assess the spectrum of products containing MI or methylchloroisothiazolinone (MCI)/MI in patients positive to MI which elicited current allergic contact dermatitis. A cross-sectional survey was performed in 2016 and 2017, including all adult patients patch tested with the baseline series (including MI 0.2% aq.) between 1 May and 31 October at 14 centres in 11 European countries. Patients with positive reactions (+ to +++) to MI were further examined regarding history, clinical characteristics and eliciting products, which were categorized into 34 types and 4 classes (leave-on, rinse-off, household, occupational). The results were compared with the reference year 2015. A total of 317 patients, n=202 of 4278 tested in 2016 (4.72%) and n=115 of 3879 tested in 2017 (2.96%), had positive reactions to MI; the previous result from 2015 was 5.97% (P<0.0001). The share of currently relevant contact allergy among all positive reactions declined significantly as well (P=0.0032). Concerning product classes, a relative decline of leave-on and a relative increase of rinse-off and household products was noted. The prevalence of MI contact allergy decreased by 50% from 2015 to 2017. As a consequence of regulation, the share of cosmetics products (leave-on in particular) eliciting allergic contact dermatitis is decreasing. The chosen method of analysing causative products in sensitized patients has proven useful to monitor effects of intervention.

Methylchloroisothiazolinone and methylisothiazolinone contact allergy: A retrospective cohort study from a tertiary dermatology clinic in Turkey.

Methylchloroisothiazolinone and methylisothiazolinone contact allergy: A retrospective cohort study from a tertiary dermatology clinic in Turkey.

Patch test concentrations for methylchloroisothiazolinone and methylisothiazolinone contact allergy

Patch test concentrations for methylchloroisothiazolinone and methylisothiazolinone contact allergy

Methylisothiazolinone contact allergy in Croatia: Epidemiology and course of disease following patch testing.

Methylisothiazolinone (MI) caused an epidemic of contact allergy in Europe, as shown by data from many countries, but no studies from Croatia exist. Also, data are lacking on the severity of allergic contact dermatitis (ACD) caused by MI, and its impact on quality of life and prognosis. To determine the frequency of MI contact allergy among Croatian dermatitis patients, identify causative exposures, assess the impact of disease, and study the prognosis. Data were collected for consecutive dermatitis patients with MI contact allergy patch tested in Croatia between November 2, 2015 and November 3, 2016. MI contact allergy was diagnosed in 13.2% of 798 tested patients. The most frequent dermatitis locations were the hands (76%) and face (61%). In 89.3% of patients, MI contact allergy was found to be of current relevance. Considerable severity and impact on daily life of disease was found at the first consultation, but this significantly decreased until follow-up 3 months later. Patch testing is the standard method for the diagnosis of ACD, and it has been shown to have an important beneficial effect on prognosis. The severity of MI ACD and the impact on daily life emphasize the need for prevention.

The methylisothiazolinone contact allergy epidemic in Australia.

The methylisothiazolinone contact allergy epidemic in Australia.

Patterns of concomitant allergic reactions in patients suggest cross-sensitization between octylisothiazolinone and methylisothiazolinone.

Recent animal tests have indicated cross-reactivity between methylisothiazolinone (MI), octylisothiazolinone (OIT), and benzisothiazolinone (BIT). To retrospectively analyse concomitant reactions to different isothiazolinones in patients in an occupational dermatology clinic during the ongoing MI contact allergy epidemic. We searched patch test files (January 2012 to February 2017) for patients with allergic reactions to OIT, BIT, and MI, and analysed their patch test results, occupations, exposure, and diagnoses. We found 61 (9.4%) allergic reactions to MI, 19 (2.9%) reactions to OIT and 9 (1.4%) reactions to BIT in a total of 647 consecutively tested patients. Seventeen (89%) of the OIT-positive patients had concomitant reactions to MI, whereas only 3 (33%) BIT-positive patients had allergic reactions to MI. The MI reactions in OIT-positive patients were almost exclusively extreme reactions (+++). Exposure to OIT was identified in 26% of the OIT-positive patients, and 56% of the BIT-positive patients had been exposed to BIT. Allergic reactions to OIT were strongly associated with extreme reactions to MI, which suggests cross-sensitization. In contrast, BIT reactions were mostly independent.

The epidemic of methylisothiazolinone: a European prospective study.

The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required. To describe demographics and MI exposures for European patients with MI contact allergy. Eleven European dermatology departments from eight European countries prospectively collected data between 1 May and 31 October 2015 among consecutive patients who had positive patch test reactions to MI (2000 ppm aq.). A total of 6.0% (205/3434; range 2.6-13.0%) of patients had positive patch test reactions to MI. Dermatitis most frequently affected the hands (43.4%), face (32.7%), arms (14.6%), and eyelids (11.7%); 12.7% had widespread dermatitis. For 72.7% (149/205), MI contact allergy was currently relevant mainly because of exposure to cosmetic products (83.2%; 124/149). Of these 124 patients, 19.5% were exposed to leave-on and rinse-off cosmetic products, 24.8% only to leave-on cosmetic products and 38.9% only to rinse-off cosmetic products containing MI or methylchloroisothiazolinone/MI. The majority of these (79%) noted onset of their dermatitis between 2013 and 2015. Fifteen patients (7.3%) had previously experienced allergic reactions when they were in newly painted rooms. Clinically relevant MI contact allergy remains prevalent across European countries, mainly because of exposure to rinse-off and leave-on cosmetic products.

Methylisothiazolinone contact allergy - are rinse-off cosmetics and household products relevant sources of exposure?

Methylisothiazolinone contact allergy - are rinse-off cosmetics and household products relevant sources of exposure?

Methylchloroisothiazolinone/Methylisothiazolinone and Methylisothiazolinone Sensitivity in Hungary.

Background. Due to allowing of methylisothiazolinone (MI) in cosmetics, cleaning products, and paints, an epidemic of MI-hypersensitivity emerged. Patch testing Kathon CG® (3:1 mixture of methylchloroisothiazolinone and methylisothiazolinone, MCI/MI) does not correctly detect MI contact allergy, due to the low concentration of MI in the test material. Methods. A retrospective survey was performed to estimate the prevalence of MCI/MI hypersensitivity in 14693 patients tested consecutively between 1993 and 2014. Moreover, currently 314 patients were prospectively tested with the allergens MCI/MI and with MI during one year. Results. MCI/MI hypersensitivity increased retrospectively from 0.5% to 6.0%. By current prospective testing we detected 25 patients (8%) with MCI/MI and/or MI positive reactions. Out of the 25 patients 10 were only MCI/MI positive, 9 were only MI positive, and 6 were MCI/MI and MI positive. If MI had not been tested separately, MI contact allergy would have missed in 36% of all detected cases and in 2.8% of the total 314 patients. Conclusions. The frequency of MCI/MI hypersensitivity is increasing also in Hungary. We confirm that, in order to detect MI contact allergy, it needs to be tested separately. A further increase of MI hypersensitivity might be expected in the future as products containing MI are still widely available.

Review of the 94th Annual Meeting of the British Association of Dermatologists, Glasgow 2014.

This is a review of the 94th Annual Meeting of the British Association of Dermatologists, held in Glasgow from 1 to 3 July 2014. The conference covered some of the latest developments in the treatment of atopic dermatitis, psoriasis and cancer, a follow-up on the methylisothiazolinone contact allergy epidemic, advances in genetically inherited disorders and somatic mutations underlying birth marks. In addition, there was an international perspective on vitiligo, leprosy and HIV, and a session discussing the regulatory process behind pharmaceutical development.

Is methylisothiazolinone contact allergy a risk factor for polysensitization?

Keywords: methylchloroisothiazolinone; contact allergy; contact dermatitis; cosmetics; methylisothiazolinone; occupational diseases; patch test; preservatives

Methylchloroisothiazolinone and methylisothiazolinone contact allergy: an occupational perspective.

Sensitivity to either methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) or MI has increased, with a reported frequency of up to 11.1% among dermatitis patients, the main context being allergic contact dermatitis caused by MCI or MCI/MI in personal care products. Case reports have described occupational allergic contact dermatitis caused by MI in paints and within the beauty industry. This study identified incident cases of occupational allergic contact dermatitis caused by MCI/MI and or MI reported from 1996 to 2012 to a UK-wide surveillance scheme (EPIDERM), with the aim of identifying changes in incidence over the study period. The data show an increase in occupational allergic contact dermatitis caused by MCI/MI and or MI from 1996 to 2012 of 4.1% [95% confidence interval (CI) 1.6-6.9] per annum. Analysis by industry showed a 3.8% (95% CI: -0.3 to 8.0) per annum increase in those exposed to personal care products in the workplace as a primary exposure [healthcare workers, 8.1% (95% CI: 2.1-14.4) per annum; beauty workers, 6.6% (95% CI: -2.2 to 16.2) per annum; hairdressers, 1.5% (95% CI: -4.7 to 8.1) per annum]. There was a 6.3% (95% CI: 1.8-10.9) per annum increase for manufacturing workers. A statistically significant rise in the frequency of occupational allergic contact dermatitis was shown to be attributable to MCI/MI and or MI between 1996 and 2012. The findings support recommendations for a review of the regulations relating to MCI/MI and/or MI in cosmetic and personal care products and in industrial settings.

Prevalence of methylchloroisothiazolinone and methylisothiazolinone contact allergy in facial dermatitis: a single centre Irish study.

There has been an increase in methylchloroisothiazolinone (MCI) and especially methylisothiazolinone (MI) contact allergy in recent years. We examined the prevalence and demography of MCI/MI and MI contact allergy in patients presenting with facial dermatitis. Eighty patients with facial dermatitis were patch tested to the British Society for Cutaneous Allergy standard series, preservatives and own products between January 2012 and March 2014. A total of 14 (17.5%) patients had positive reactions to this preservative. Five (6.3%) patients tested positive to MCI/MI (0.02%), four (5%) patients tested positive to MI (0.2%) and five (6.3%) patients tested positive to both preparations. Six (7.5%) of these patients were atopic. All patients were female and the mean age was 53.8 years. Sources of allergen were in cosmetics and skin care products. Contact allergies to MCI/MI and MI are commoner than what was reported before and is an emerging cause of facial dermatitis. The detection rate of this allergen was increased by 5% in our cohort since the inclusion of MI (0.2%) in the standard series.

Methylisothiazolinone Contact Allergy is Rising to Alarming Heights Also in Southern Sweden

The preservative methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) is a well-known sensitiser and present in most baseline series since at least 20 years. The proportions of MCI/MI are 3:1. MI alone has been used as a preservative in occupational and household products, and cosmetics since less than 10 years. MCI/MI tested at 100 ppm fails to detect a significant percentage of contact-allergic reactions to MI. Our aim was to investigate whether a separate test preparation with MI picks up additional cases of contact allergy to MI not detected with MCI/MI 200 ppm. MI was inserted into the baseline series of the Malmö clinic in 2003 starting at 475 ppm, then 900 ppm, then 1,000 ppm, 1,500 ppm and finally 2,000 ppm. In 5,881 consecutively tested dermatitis patients the contact allergy rate for MI varied between 0.5 and 6.5%, with a marked increase in recent years. The contact allergy rate to MI 2,000 ppm alone, not traced by MCI/MI 200 ppm, varied between 0 and 1.9 %. In conclusion, due to the increase of contact allergy to MI not traced by MCI/MI 200 ppm, MI in water at 2,000 ppm should be tested in a baseline series. Independent of patch test technique a dose of 60 µg/cm should not be exceeded to avoid adverse reactions and particularly patch test sensitisation.

Methylisothiazolinone and benzisothiazolinone are widely used in paint: a multicentre study of paints from five European countries.

In view of the current epidemic of contact allergy to methylisothiazolinone (MI), it is important to clarify the extent of use of MI and related isothiazolinones in paints currently available for the consumer and worker in Europe. To elucidate the use and concentrations of MI, methylchloroisothiazolinone (MCI) and benzisothiazolinone (BIT) in paints on the European retail market. Wall paints (n = 71) were randomly purchased in retail outlets in five European countries. The paints were quantitatively analysed for their contents of MI, MCI and BIT by high-performance liquid chromatography coupled to tandem mass spectrometry. MI was found in 93.0% (n = 66) of the paints, with concentrations ranging from 0.7 to 180.9 ppm, MCI in 23.9% (n = 17), ranging from 0.26 to 11.4 ppm, and BIT in 95.8% (n = 68), ranging from 0.1 to 462.5 ppm. High concentrations of MI were found in paints from all five countries. Paints purchased in Denmark and Sweden contained especially high concentrations of BIT. The use of MI across European countries is extensive. In view of the ongoing epidemic of MI contact allergy, an evaluation of the safety of MI in paints is needed.

Occupations at risk of developing contact allergy to isothiazolinones in Danish contact dermatitis patients: results from a Danish multicentre study (2009-2012).

In recent years, the prevalence of contact allergy to isothiazolinones has reached epidemic levels. Few studies have presented data on occupations at risk of developing contact allergy to isothiazolinones. To present demographics and examine risk factors for sensitization to methylisothiazolinone (MI), methylchloroisothiazolinone (MCI) in combination with MI and benzisothiazolinone (BIT) in Danish dermatitis patients. A retrospective epidemiological analysis of data from three Danish hospitals departments was conducted. All patients consecutively patch tested with MI, MCI/MI and BIT between 2009 and 2013 were included. MI contact allergy showed a significantly increased trend in prevalence from 1.8% in 2009 to 4.2% in 2012 (p < 0.001). Females with facial dermatitis mainly drove the increase in 2012. Adjusted logistic regression analysis showed that MI sensitization was significantly associated with occupational exposures, hand and facial dermatitis, age > 40 years, and the occupational groups of tile setters/terrazzo workers, machine operators, and painters. MCI/MI contact allergy was significantly associated with the following high-risk occupations: painting, welding (blacksmiths), machine operating, and cosmetology. The occupational group of painting was frequent in the group of patients with BIT contact allergy. Several high-risk occupations for sensitization to isothiazolinones exist. Regulation on the allowed concentration of isothiazolinones, and especially MI, in both consumer products and industrial products is needed.

The dramatic increase in the rate of methylisothiazolinone contact allergy in Belgium: a multicentre study.

The rate of contact allergy and allergic contact dermatitis caused by methylisothiazolinone (MI) is dramatically increasing throughout Europe. To report on methylchloroisothiazolinone (MCI)/MI and MI allergy in Belgium. Between January 2010 and December 2012, the medical charts of 6599 patients of the Belgian Contact and Environmental Dermatitis Group were retrospectively reviewed for MCI/MI and MI sensitization by use of a standardized questionnaire. Available data on sensitization in 2081 patients tested in 2013 were also included. In 2012, the sensitization rate for MCI/MI had increased to 4.5% and that for MI to 6.0%; the latter showed a further increase to 7.2% in 2013. The people mainly affected were women with a median age of 49years with hand and/or facial dermatitis, most often resulting from the use of cosmetics. Simultaneous reactions to octylisothiazolinone were observed. A dramatic increase in the rate of contact allergy caused by MI in cosmetics is occurring in Belgium. Notwithstanding the recent recommendation to discontinue the use of MI in leave-on cosmetics, safer use concentrations should also be determined for rinse-off products. Close monitoring of MI sensitization in the near future will be necessary, and the highest test concentrations reported for MI and MCI/MI should be included in the baseline series.