Successful inhibition of allergic contact dermatitis caused by methylchloroisothiazolinone/methylisothiazolinone with topical glutathione

Demographic and clinical profile of occupational cases of sensitization to methylisothiazolinone and Kathon CG: a cross-sectional study

Abstract Introduction: methylisothiazolinone alone or associated with methylchloroisothiazolinone (Kathon CG) is a preservative related to occupational allergic contact dermatitis. Objectives: to evaluate the demographic and clinical profile of occupational cases of sensitization to isothiazolinones in the city of Rio de Janeiro and to describe the presence of these preservatives in national paints. Methods: cross-sectional study based on information from medical records of workers who underwent patch testing between 2013-2017. The prevalence of clinical, demographic and occupational characteristics was described and an unadjusted model was used to investigate the association between variables. We sought the presence and concentration of isothiazolinones in the chemical composition sheets of national paints. Results: among the 768 workers submitted to the tests, 68 had occupational dermatosis with a positive result for sensitization to methylisothiazolinone/Kathon CG. The most affected occupations were those related to domestic activities and cleaning. There was a greater likelihood of sensitization to isothiazolinones in women and in those with involvement of the hands and legs. Among the 61 paints evaluated, 26 had some isothiazolinone, with methylchloroisothiazolinone being the most common. Conclusions: sensitization to isothiazolinones can impact workers’ health and demands greater vigilance on cleaning materials and cosmetics, as well as discussing the composition regulation of the paints sold in Brazil.

Perfil demográfico e clínico de casos ocupacionais de sensibilização a metilisotiazolinona e Kathon CG: estudo seccional

Resumo Introdução: a metilisotiazolinona isolada ou associada à metilcloroisotiazolinona (Kathon CG) é um conservante relacionado à dermatite de contato alérgica ocupacional. Objetivos: avaliar o perfil demográfico e clínico dos casos ocupacionais de sensibilização a isotiazolinonas no município do Rio de Janeiro e descrever a presença desses preservativos em tintas nacionais. Métodos: estudo transversal baseado em informações de prontuários de trabalhadores submetidos a testes de contato entre 2013-2017. Descreveu-se a prevalência de características clínicas, demográficas e ocupacionais e utilizou-se um modelo não-ajustado para investigar a associação entre variáveis. Buscou-se a presença e a concentração de isotiazolinonas nas fichas de composição química de tintas nacionais. Resultados: dentre os 768 trabalhadores submetidos aos testes, 68 apresentavam dermatose ocupacional com resultado positivo para sensibilização à metilisotiazolinona/Kathon CG. As profissões mais acometidas foram as relacionadas a atividades domésticas e limpeza. Houve maior chance de sensibilização às isotiazolinonas nas mulheres e naqueles com acometimento das mãos e das pernas. Entre as 61 tintas avaliadas, 26 possuíam alguma isotiazolinona, sendo a metilcloroisotiazolinona a mais comum. Conclusões: a sensibilização às isotiazolinonas pode impactar a saúde do trabalhador e demanda maior vigilância com materiais de limpeza e cosméticos, assim como a discussão da regulação da composição de tintas comercializadas no país.

Can the Reactivity to Chromate Be Changed in Patch Testing Using a Barrier Cream?

BACKGROUND

The persistent, difficult-to-treat, allergic contact dermatitis from hexavalent chromium in European construction workers has diminished significantly since the legislative measurements that came into force in January 2005. However, sensitization to hexavalent chromium continues to be a problem. Barrier creams have been tried for various allergens with divergent results.

OBJECTIVE

The aim of the study was to investigate the protective capacity of barrier cream candidates against hexavalent chromium in a patch test situation.

METHODS

An experimental study was performed to investigate the reductive properties of glutathione and iron sulfate on the patch test reactivity in chromium-allergic individuals when exposed to hexavalent chromium. In this study, we also investigated the protective properties of a commercially available barrier cream.

CONCLUSIONS

A higher number of volunteers (16/18) showed reactions on the skin treated with the commercially available barrier cream, compared with the untreated skin (13/18) on test reading day 3/4 or day 7. The skin treated with petrolatum or Essex cream showed fewer and less prominent allergic reactions than the skin treated with the commercially available barrier cream.

Skin application of glutathione and iron sulfate can inhibit elicitation of allergic contact dermatitis from hexavalent chromium

BACKGROUND

Allergic contact dermatitis (ACD) caused by hexavalent chromium, Cr(VI), is often severe and difficult to treat. The most common source of exposure to Cr(VI) in Sweden used to be cement, and more recently leather. The contact allergy can be diminished or inhibited if the exposure is decreased or ceases. Barrier creams against different kinds of allergens have been investigated for their protective properties which may offer protection against Cr(VI) exposure.

OBJECTIVES

To investigate the capacity of formulas containing glutathione (GSH) and iron sulfate to inhibit elicitation of ACD in Cr(VI)-allergic individuals when exposed to Cr(VI).

METHODS

In 18 Cr(VI)-allergic volunteers the back was divided into eight patch test areas which were treated with preparations of possible barrier creams, prior to patch testing with a dilution series of potassium dichromate and a buffered extract of cement.

RESULTS

A significant reduction in reactivity to Cr(VI) and cement extract on skin treated with formulas containing GSH or iron sulfate was noticed, compared with untreated skin.

CONCLUSION

Formulas containing GSH or iron sulfate in barrier creams inhibit ACD in individuals allergic to Cr(VI) when applied before exposure to Cr(VI) and cement extract.

Can reducing cosmetic substances help prevent chromate contact allergy?

BACKGROUND

Allergic contact dermatitis caused by Cr(VI) is often severe and difficult to treat. Therefore, primary prevention is a main goal but, secondary prevention can be valuable to ease the symptoms or prevent relapse of Cr(VI) dermatitis when sensitization has occurred. Barrier creams have been tried for many chemical substances, but until now there is no successful barrier cream against Cr(VI).

OBJECTIVES

To investigate the ability of reducing agents to transform Cr(VI) into Cr(III) in an experimental situation, in order to find suitable chemicals to investigate for possible use in a barrier cream.

METHODS

The capacity to reduce the amount of Cr(VI) was analyzed in water solutions of acetylcysteine, cysteine, dihydroxyacetone, glutathione, and iron sulfate heptahydrate. Thereafter the reducing capacity of acetylcysteine, dihydroxyacetone, glutathione, and iron sulfate on the amount of Cr(VI) in cement extracts was investigated. The content of Cr(VI) in the test solutions and in the cement extracts was estimated by the diphenyl carbazide spot test.

RESULTS

All of the chosen chemicals reduced the amount of Cr(VI) in the test solutions and in the cement extracts to some extent. The reducing capacity was most prominent for iron sulfate.

CONCLUSION

A reducing capacity was found for all chosen chemicals.

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.