Four-year Epidemiological Surveillance of the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy: Current Situation and Trends. / Vigilancia epidemiológica en los últimos 4 años del Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea: situación actual y tendencias.

BACKGROUND: The epidemiological surveillance of contact dermatitis is one of the objectives of the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy. Knowing whether the prevalence of positive tests to the different allergens changes over time is important for this monitoring process. OBJECTIVES: To describe the various temporary trends in allergen positivity in the GEIDAC standard series from 2018 through December 31, 2022. METHODS: This was a multicenter, observational trial of consecutive patients analyzed via patch tests as part of the study of possible allergic contact dermatitises collected prospectively within the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy. The data was analyzed using 2 statistical tests: one homogeneity test (to describe the changes seen over time) and one trend test (to see whether the changes described followed a linear trend). RESULTS: A total of 11327 patients were included in the study. Overall, the allergens associated with a highest sensitization were nickel sulfate, methylisothiazolinone, cobalt chloride, methylchloroisothiazolinone/methylisothiazolinone, and fragrance mix i. A statistically significant decrease was found in the percentage of methylisothiazolinone positive tests across the study years with an orderly trend. CONCLUSIONS: Although various changes were seen in the sensitizations trends to several allergens of the standard testing, it became obvious that a high sensitization to nickel, methylchloroisothiazolinone/methylisothiazolinone and fragrances mix i remained. Only a significant downward trend was seen for methylisothiazolinone.

Preservatives in Personal Hygiene and Cosmetic Products, Topical Medications, and Household Cleaners in Spain. / Conservantes en productos de higiene y cosméticos, medicamentos tópicos y productos de limpieza doméstica en España.

INTRODUCTION: Preservatives are added to cosmetic, household cleaning, and other industrial products to prevent the growth of microorganisms. Unfortunately, exposure to these substances can cause sensitization. MATERIAL AND METHODS: Between January and June 2015, we analyzed the ingredients of 2300 products commercially available in Spain to identify the frequency of a wide variety of preservatives in different product categories. We analyzed 1093 skin care and cosmetic products sold exclusively in pharmacies (dermocosmetics), 458 household cleaning and personal hygiene and cosmetic products sold in supermarkets, 636 topical medications, and 113 cosmetic products sold in a herbal shop. RESULTS: Phenoxyethanol, citric acid, sodium benzoate, and potassium sorbate were very common in all the cosmetic product categories. Parabens were present in 16.1% of dermocosmetic products, 14.45% of cosmetic products available in supermarkets, 0.88% of cosmetic products available in the herbal shop, 5.18% of topical medications, and in none of the cleaning products. Isothiazolinones were identified in 2.56% of dermocosmetic products, 18% of cosmetic products in supermarkets, 7.9% of cosmetic products in the herbal shop, 63.63% of household cleaners, and in none of the topical medications. Formaldehyde releasers were detected in 5.76% of dermocosmetic products, 6.42% of cosmetic products sold in supermarkets, 7.96% of cosmetic products sold in the herbal shop, 3.93% of topical medications, and 16.74% of household cleaners. CONCLUSIONS: Evaluation of the presence of preservatives in everyday products allows us to indirectly estimate exposure levels to each one. Measures restricting the use of the most problematic preservatives need to be strengthened.

Update on allergic contact dermatitis due to methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone.

The combination of methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) is widely used as a preservative in cosmetics, household, and industrial products. Furthermore, MI at a concentration of 100 ppm has been permitted in cosmetic products since 2005. Recently, a considerable increase in cases of contact dermatitis to both MCI and MI have been noted, and this warrants closer monitoring by relevant authorities and, probably, stricter legislation. In fact, MI at a test concentration of 2000 ppm was recently included in the European baseline patch test series. The clinical manifestations of allergy to MCI/MI and MI are highly variable and diagnosis is often missed. In the standard patch test series of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC), MCI/MI is tested at 100 ppm, but at this concentration, up to 50% of cases might go undetected. Furthermore, our data indicate that MCI/MI at 200 ppm would make it possible to diagnose more cases of contact allergy to MI. To improve the diagnosis of contact allergy to MCI/MI and MI, we believe that the test concentration of MCI/MI should be increased to 200 ppm in the GEIDAC standard series and that MI should be added in the GEIDAC standard series.

Descriptive study of sensitization to methylchloroisothiazolinone and methylisothiazolinone in a skin allergy unit.

BACKGROUND: Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are heterocyclic compounds used as preservatives in cosmetic and industrial products. They continue to be common allergens, causing positive patch test reactions in 2% to 4% of patients tested. MATERIAL AND METHODS: We searched the database at our skin allergy unit for all cases of sensitization to MCI/MI and MI diagnosed between January 1980 and March 2013. RESULTS: Patch tests were performed with MCI/MI in 8705 patients and with MI in 404 patients. In total, 222 patients (2.55%) were sensitized to MCI/MI and 21 (5.19%) were sensitized to MI. The incidence of MCI/MI cases peaked between 1998 and 2005 and again between 2009 and 2013. Of the 222 patients with MCI/MI sensitization, 142 were women (64%) and 49 were men (36%); the mean age was 43 years. The most frequently affected areas were the hands (54% of cases), the arms (36%), and the face (35%); 75.67% of cases were due to cosmetics and 2.25% were due to paint. Of the 21 patients with MI sensitization (mean age, 50 years), 12 were women (57%) and 9 were men (43%). The most common site of involvement in this group was the face (71% of cases), followed by the arms (38%) and the hands (29%). All the cases were due to cosmetics. CONCLUSIONS: Our data show that sensitization to the combination of MCI and MI and MI alone has increased in recent years. It would appear to be necessary to add MI to the baseline patch test series, although the test concentration has yet to be determined.

Alergia à Metilisotiazolinona: Relato de caso / Methylisothiazolinone Allergy: Case Report

A metilisotiazolinona (MI) é um conservante presente em produtos químicos de limpeza e cosméticos na forma isolada ou associada à metilclorotiazolinona (MCI/MI). Seu uso tem sido associado ao aumento progressivo de casos de dermatite alérgica de contato (DAC) no mundo, constituindo uma das principais causas dessa entidade. O diagnóstico padrão-ouro de DAC a essa substância é realizado pelo teste de contato. No Brasil, a bateria padrão contempla apenas o composto MCI/MI, não avaliando isoladamente a MI. Relatamos caso clínico de uma paciente com eczema crônico predominante em mãos, que possuía nexo ocupacional com utilização de produtos de limpeza, tendo apresentado teste de contato, através da bateria Latino-Americana, fortemente positivo (+++) à MI 0,2% e negativo para MCI/MI. Objetivamos demonstrar a importância da inclusão da metilisotiazolinona, de forma isolada, na bateria padrão brasileira para maior sensibilidade diagnóstica, além da necessidade de especificação da presença desse conservante em produtos de limpeza.

Methylisothiazolinone (MI) is a preservative present in cleaning and cosmetic products, in the isolated form or associated to methylchloroisothiazolinone (MCI/MI). Its use has been associated with the progressive increase in cases of allergic contact dermatitis (ACD) in the world, constituting one of the main causes of this entity. The gold standard diagnosis of ACD for this substance is performed by the patch test. In Brazil, the baseline series only includes the MCI / MI compound, not evaluating the MI alone. We case report of a patient with predominant chronic eczema on the hands, who had an occupational nexus with the use of cleaning products, having presented a patch test, through the Latin American series, extremely positive for 0.2% MI (+++) and negative for the MCI/MI. We aim to demonstrate the importance of including methylisothialzoninone, in isolation, in the Brazilian baseline series for greater diagnostic sensitivity, in addition to the need to specify the presence of this preservative in products.

Dermatite de contato à metilisotiazolinona ­ estamos atentos a essa epidemia? / Contact dermatitis due to methylisothiazolinone ­ are we aware of this epidemic?

Metilclorotiazolinona e metilisotiazolinona (MCI/MI) são os ingredientes ativos no Kathon CG®, um conservante de cosméticos no mercado desde os anos 80. Eles aparecem numa mistura de conservantes na proporção de 3:1. Metilisotiazolinona (MI) isolada tinha sido aprovada como conservante desde 2005, uma vez que foi considerada menos sensibilizante comparado à porção clorada. Entretanto, ela tem sido usada numa concentração muito maior para ser efetiva, e isso tem causado a atual epidemia de alergia a essa substância. O objetivo dessa revisão foi examinar o atual surto de casos de alergia de contato a metilisotiazolinona (MI) no mundo, um fenômeno que tem sido observado em vários países, inclusive no Brasil. As fontes de dados incluíram os principais artigos originais e revisões indexadas nos bancos de dados PubMed, MEDLINE, LILACS e SciELO que foram publicadas nos últimos anos. Os resultados mostram elevado grau de positividade de testes de contato tanto à associação MCI/MI quanto à MI isolada, e significativo aumento da prevalência de alergia a esta substância nos últimos anos. Em conclusão, alertamos que devemos estar atentos a esse importante conservante. Salientamos que a associação MCI/MI nos testes pode não diagnosticar casos de alergia à MI. Apesar dessa substância isolada não se encontrar na bateria padrão brasileira, a pesquisa de sua sensibilidade é fundamental.

Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are the active ingredients in Kathon CG®, a cosmetic preservative available in the market since the 80s. MCI and MI are mixed in a ratio 3:1. MI alone was approved for use as a preservative in 2005, as it was considered a less sensitizing agent compared to chlorine. However, it has been used at a much higher concentration to be effective and this has caused the current epidemic of allergy to this substance. This review aimed to examine the current outbreak of cases of contact allergy to MI observed in several countries, including Brazil. Data sources were major original articles and reviews indexed in PubMed, MEDLINE, LILACS and SciELO databases and published in recent years. The results showed a high rate of positive tests for allergy both to MCI/MI combination and to MI alone, as well as a significant increase in the prevalence of allergy to this substance in recent years. In conclusion, this common preservative requires attention. Importantly, MCI/MI combination tests may not diagnose cases of allergy to MI alone. Although this substance is not found alone in the Brazilian standard battery, research on its sensitivity is essential.