Chlorhexidine in cosmetic products - a market survey.

BACKGROUND: Chlorhexidine may cause type I and type IV allergy. Some chlorhexidine-allergic individuals have been exposed in the healthcare setting as patients or healthcare workers, but for others the source of sensitization is unknown. Chlorhexidine may be used as a preservative or an antimicrobial agent in cosmetic products at a concentration up to 0.3%, as set by the European Cosmetics Directive (now Regulations). OBJECTIVES: To identify cosmetic product types containing chlorhexidine, and to measure the concentration of chlorhexidine in selected products. METHODS: Between February 2013 and April 2013, we checked for chlorhexidine in cosmetic products in 14 supermarkets, one hairdressing salon and one beauty and retail store in Copenhagen, Denmark by reading the ingredient labels. The chlorhexidine concentration was measured in 10 selected products by high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector. RESULTS: Chlorhexidine was found in 80 of 2251 checked products (3.6%) in the following categories: hair products (57/760), creams (9/324), face washes (4/24), wet wipes (4/63), skin tonics (3/22), make-up removers (2/25), and mouth washes (1/17). Chlorhexidine concentrations were 0.01-0.15%. CONCLUSIONS: We found chlorhexidine in various cosmetic product types, predominantly aimed at females, and in hair products. The measured chlorhexidine concentrations were all within the permitted limit. The relevance for allergic sensitization should be further explored.

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

BACKGROUND: 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. OBJECTIVES: To elucidate the use and concentrations of MI, methylchloroisothiazolinone (MCI) and benzisothiazolinone (BIT) in paints on the European retail market. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Emission of isothiazolinones from water-based paints.

The isothiazolinone preservatives methylisothiazolinone (MI), methylchloroisothiazolinone (MCI), and benzisothiazolinone (BIT) are used in a wide variety of products including paint and cosmetics, and they are known to cause allergic contact dermatitis. Among painters they are one of the most common causes of contact dermatitis. Furthermore, they are all volatile, and severe reactions caused by emissions of especially MI from paint have been reported recently. In this study the concentrations of MI, BIT, and MCI in water-based paint were analyzed by LC-MS-MS, and the emissions from the paints were measured in climate chambers and in an apartment. Nineteen paints were analyzed for the content of MI, MCI, and BIT. All 19 paints contained MI, 16 contained BIT, and 4 contained MCI. In the chamber experiment emission of MI peaked within hours of application but then continued at a slow rate for more than 42 days. MCI was emitted more slowly and peaked after several days. BIT emissions were all around the limit of detection. In the apartment we were able to detect emission of MI several days after application. Long lasting evaporation and thus chronic exposure give credibility to the clinical observations that MI can be an important cause of airborne contact dermatitis among painters and consumers.

Methylisothiazolinone contact allergy--growing epidemic.

BACKGROUND: The prevalence of contact allergy to the isothiazolinone preservative methylchloroisothiazolinone (MCI) in combination with methylisothiazolinone (MI) and MI alone has increased in the last couple of years. OBJECTIVES: To investigate the prevalence of contact allergy to MI, MCI/MI and benzisothiazolinone (BIT) among patch tested patients at Gentofte Hospital, as well as the use of MI in cosmetic products. METHODS: Patients patch tested with either MI, MCI/MI or BIT from 2010 to 2012 were included in the study. The MOAHLFA index was registered in all patch tested patients, and relevant exposures were determined in patients with an isothiazolinone allergy. In a market survey, the ingredient labels of cosmetic products were investigated for MI content. RESULTS: The prevalence of MI and MCI/MI contact allergy increased significantly from 2010 to 2012: from 2.0% to 3.7% for MI (n = 2766), and from 1.0% to 2.4% for MCI/MI (n = 2802). MI-allergic patients had occupational, hand and face dermatitis significantly more often, and were aged > 40 years. Cosmetics were the most common substances causing relevant exposure found in both MCI/MI-allergic and MI-allergic patients. MI was found in 3.3% of cosmetics on the Danish retail market. CONCLUSIONS: The increase in MI contact allergy is alarming, and urgent action is needed.

Occupational contact dermatitis in painters: an analysis of patch test data from the Danish Contact Dermatitis Group.

BACKGROUND: Painters are among the occupational groups that most commonly experience occupational contact dermatitis, but few investigations exist concerning this occupation. OBJECTIVES: To characterize painters with contact dermatitis and identify the most common allergens associated with the occupation. Materials and methods. All patch test results of 219 painters and 1095 matched controls registered by the Danish Contact Dermatitis Group between 2001 and 2010 were analysed. RESULTS: Hand eczema (p < 0.0001) and occupational contact dermatitis (p < 0.0001) were observed significantly more often in the painters than in the group of controls. Sensitizations to the following allergens from the European baseline series were associated with the occupation and were statistically significant: methylchloroisothiazolinone/methylisothiazolinone, epoxy resin, formaldehyde, and quaternium-15. Three different isothiazolinones emerged as the most frequent sensitizers of the allergens tested in addition to the baseline series. CONCLUSIONS: The results indicate that painters have an increased risk of developing occupational hand eczema. Isothiazolinones and epoxy resin proved to be the two most frequent sensitizers in painters.

Methylisothiazolinone contact allergy and dose-response relationships.

BACKGROUND: Methylisothiazolinone (MI) used alone is a new preservative causing a high prevalence of contact allergy. The eliciting threshold of MI is unknown. The combination of MI and phenoxyethanol enhances the antimicrobial efficacy of MI. OBJECTIVES: The eliciting doses of MI contact allergy in a patch test and a repeated open application test (ROAT) were investigated. In the patch test, it was determined whether phenoxyethanol influenced the reactivity to MI. METHODS: Eleven MI-allergic individuals were patch tested with two dilution series of 12 doses of MI and the same 12 doses with phenoxyethanol. The ROAT mimicked the use of a cream preserved with 100, 50 and 5 ppm MI (corresponding to 0.21, 0.105 and 0.0105 µg MI/cm(2)). RESULTS: Phenoxyethanol had no influence on the reactions to MI. The lowest eliciting dose in the patch test was 1.47 µg MI/cm(2). In the ROAT, 7 patients (64%) reacted to 0.21 and 0.105 µg MI/cm(2) and 2 patients (18%) reacted to 0.0105 µg MI/cm(2), corresponding to a cream preserved with 5 ppm MI. CONCLUSIONS: A maximum of 100 ppm MI is permitted in cosmetic products. Eighteen per cent of MI-allergic patients reacted to a concentration 20 times lower in a ROAT. The amounts used in cosmetics should be reduced, and the development of MI contact allergy should be monitored closely.

Prevalence and cause of methylisothiazolinone contact allergy.

BACKGROUND: Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) has been one of the most frequent sensitizers since the 1980s. In 2005, the use of MI alone was approved for the preservation of cosmetic and household products in the EU. Before that, MI was used in industrial products, and the first cases of isolated MI contact allergy were published. OBJECTIVES: To present the prevalence and causes of MI contact allergy. MATERIALS AND METHODS: Patch test results from 2536 dermatitis patients tested with MI at Gentofte University Hospital between May 2006 and February 2010 were analysed. A retrospective investigation of medical records from MI-allergic patients was performed to reveal the causes of their MI contact allergy. RESULTS: Of patch-tested patients, 1.5% had MI contact allergy. It was associated with occupational dermatitis, hand eczema and age above 40 years. Exposure to MI in cosmetic products was found in 12 (32%) cases, and exposure to MI in occupational products was found in 11 (30%) cases; 5 of the 11 were painters. CONCLUSIONS: The prevalence of MI contact allergy is already at the same level as that of other sensitizing preservatives, which have been on the market for several years, but no rising trend was identified. MI contact allergy was associated with both occupational and consumer products.

Temporal trends of preservative allergy in Denmark (1985-2008).

BACKGROUND: Most cosmetics and industrial products contain preservatives. Preservative allergy is common and, historically, changing contact allergy epidemics caused by preservatives have been observed. In 1997, Alan Dillarstone predicted a stable development of preservative allergy following mandatory ingredient labelling on cosmetic products. OBJECTIVES: To investigate the development in the prevalence of preservative allergy in Denmark over a 24-year period (1985-2008) and to challenge the prediction made by Dillarstone. PATIENTS/METHODS: A retrospective analysis of patch test data was performed (n = 18179). Comparisons were made using a chi(2) test. Logistic regression analyses were used to test for associations. RESULTS: The development of preservative allergy mirrored those of other European patch test centres. The development was not dependent on sex or age group. The prevalence was higher among women and those aged 41-60 years. Formaldehyde allergy was persistently prevalent over the study years. The overall prevalence of preservative allergy increased significantly (P(trend) = 0.001), mainly because of patch testing with additional preservatives in recent years. CONCLUSIONS: Dillarstone's prediction was confirmed as the prevalence of contact allergy to individual preservatives remained relatively stable. However, the overall burden of preservative allergy seemed to increase. Introduction of new preservatives may add to the burden of contact allergy.

Formaldehyde exposure and patterns of concomitant contact allergy to formaldehyde and formaldehyde-releasers.

BACKGROUND: Formaldehyde and formaldehyde-releasers are widely used in consumer products and may often cause contact allergy. OBJECTIVE: To investigate the prevalence of concomitant contact allergy to formaldehyde and formaldehyde-releasers in dermatitis patients, and to determine the sources of formaldehyde exposure based on personal and occupational products obtained from dermatitis patients. METHODS: Patch test data from referred dermatitis patients with a positive patch test reaction to formaldehyde or formaldehyde-releasers were analysed. For the period 2000-2008, the formaldehyde content in products obtained from formaldehyde-allergic patients was analysed by chromotropic acid test and/or acetylacetone test. RESULTS: Patients allergic to a formaldehyde-releaser often had simultaneous contact allergy to formaldehyde. Other combinations were also prevalent. In patients who reacted to more than two formaldehyde-releasers, nearly all reacted simultaneously to formaldehyde. Seventy-five percent of the formaldehyde-allergic patients used a product that contained formaldehyde. The main source of formaldehyde exposure was cosmetics (78%). CONCLUSIONS: Concomitant contact allergy to formaldehyde and formaldehyde-releaser remains common. Furthermore, contact allergy to a formaldehyde-releaser was nearly always concomitant with another formaldehyde-releaser. Formaldehyde was commonly found in personal products used by formaldehyde-allergic patients.