High rate of sensitization to Kathon CG, detected by patch tests in patients with suspected allergic contact dermatitis

Abstract Background: Kathon CG, a combination of methylchloroisothiazolinone and methylisothiazolinone, is widely used as preservative in cosmetics, as well in household cleaning products, industrial products such as paints and glues. It has emerged as an important sensitizing agent in allergic contact dermatitis. Objectives: This study evaluated the reactivity to this substance in patients subjected to patch tests at the Dermatology Institute in Bauru, São Paulo from 2015 to 2017 and its correlation with other preservatives, the professional activity and location of the lesions. Methods: The patients were submitted to standard series of epicutaneous tests, standardized by the Brazilian Group Studies on Contact Dermatitis. Results: Out the 267 patients tested, 192 presented positivity to at least one substance and 29 of the patients (15.10%) presented reaction to Kathon CG, with predominance of the female gender (n = 27); main professional activity associated with Kathon CG sensibilization was cleaning (17.24%), followed by aesthetic areas (13.79%) and health care (10.34%). The most prevalent sensitizations among the substances tested were nickel sulphate (56.3%), followed by cobalt chloride (23.4%), neomycin (18.2%), potassium dichromate (17.7%), thimerosal (14.5%), formaldehyde (13.2%), paraphenylenediamine (9.3%), and fragrance mix (8.3%). Study limitations: We do not have data from patients that were submitted to patch test a decade ago in order to confront to current data and establish whether or no sensitization to Kathon CG has increased. Conclusion: High positivity to Kathon CG corroborates the recent findings in the literature, suggesting more attention to concentration of this substance, used in cosmetics and products for domestic use.

Sociodemographic and clinical profile of patients with occupational contact dermatitis seen at a work-related dermatology service, 2000 - 2014

Abstract: BACKGROUND: Occupational dermatoses are common, especially contact dermatitis. Epidemiological studies on these dermatoses are scarce in Brazil and they are necessary as part of the public policy to protect workers' health. OBJECTIVES: To identify sociodemographic and clinical profile of patients with occupational contact dermatitis seen between 2000 and 2014 at an occupational dermatology service. METHODS: It is a cross-sectional and retrospective study, based on information obtained from the service's database. RESULTS: Of 560 patients with conclusive patch test, 289 (46.9%) presented occupational dermatoses and 213 occupational contact dermatitis with predominance of the allergic type in relation to the irritative type (149:64 respectively). The odds of occupational dermatoses were higher among men and lower among patients aged 50 years or older and with higher level of education. Regarding the possibility of presenting occupational allergic contact dermatitis, only the gender variable was statistically significant. The professions most seen were cleaners, construction workers, painters, mechanics/metallurgists and cooks. The commonest allergens were nickel sulfate, potassium dichromate, cobalt chloride, carba-mix and formaldehyde. STUDY LIMITATIONS: The main limitations of this study are the fact that it was carried out in a tertiary service of occupational dermatoses and the lack of access to some allergens outside the patch test baseline series. CONCLUSIONS: It was possible to identify the sociodemographic and clinical profile of patients with suspected occupational contact dermatitis seen at the Service, beyond the professional groups and allergens related to a high risk of occupational contact dermatitis in this population.

Patch-test results in children and adolescents: systematic review of a 15-year period

Abstract The number of studies on patch-test results in children and adolescents has gradually increased in recent years, thus stimulating reviews. This paper is a systematic review of a 15-year period devoted to studying the issue. Variations pertaining to the number and age groups of tested children and/or adolescents, the number of subjects with atopy/atopic dermatitis history, the quantity, type and concentrations of the tested substances, the test technique and type of data regarding clinical relevance, must all be considered in evaluating these studies, as they make it harder to formulate conclusions. The most common allergens in children were nickel, thimerosal, cobalt, fragrance, lanolin and neomycin. In adolescents, they were nickel, thimerosal, cobalt, fragrance, potassium dichromate, and Myroxylon pereirae. Knowledge of this matter aids health professionals in planning preventive programs aimed at improving children's quality of life and ensuring that their future prospects are not undermined.

Dermatitis alérgica de contacto por cosméticos en un consultorio alergoinmunologico / Allergic dermatitis of contact by cosmetics in a alego-immunological doctor`s office

La dermatitis de contacto (DC) es una respuesta inflamatoria de la piel, como resultado del contacto de la misma con múltiples factores externos, frecuentemente contenidos en cosméticos. Las pruebas del parche son el pilar diagnostico. Se evaluó la prevalencia de la dermatitis alérgica de contacto por cosméticos, determinando las relaciones epidemiológicas como: edad, sexo, localización, ocupación y sensibilización. El 70% de los pacientes estudiados fueron DAC y el 30% fuerondermatitis irritativas por contacto (DIC). El 57% de las dermatitis alérgicas estaban asociadas a cosméticos,predominando en el sexo femenino.

Contact dermatitis (AD) is an inflammatory response of the skinas a result of contact with multiple external factors, often containedin cosmetics. Patch tests are the diagnostic pillar. Prevalence of allergic contact dermatitis to cosmetics was evaluatedby determining the epidemiological relationships as age, sex, location, occupation and awareness.70% of the patients studied were DAC and 30% were irritant contact dermatitis (ICD).57% of allergic dermatitis were associated with cosmetics, predominantly in females.

Evaluation of the permanence of skin sensitization to allergens in patients with allergic contact dermatitis / Avaliação da persistência de sensibilização a alérgenos em pacientes com diagnóstico de dermatite alérgica de contato

BACKGROUND: Background: Patch tests are an efficient method to confirm the etiological diagnosis of allergic contact dermatitis. OBJECTIVES: 1) To determine the permanence of results between two tests performed with an interval of at least one year, in patients with allergic contact dermatitis; 2) To compare the positive results according to rates of intensity; 3) To evaluate the permanence of sensitization according to each substance that was tested. METHODS: Patients with previous diagnosis of allergic contact dermatitis, confirmed by patch tests carried out between the years 2005 and 2008, underwent new testing, using the same methodology, and data was compared. RESULTS: A total of 1470 results of both tests on 49 patients were analyzed. The negative results remained in the second test in a rate of 96%, and 4% became positive (+) without relevance to the clinical history. Moreover, moderately (++) and strongly (+++) positive results were also maintained in, respectively, 86% and 100%. Nevertheless, weakly (+) positive results became negative in 65%. By ignoring all weakly (+) positive tests, the calculation of Kappa Index of Agreement Statistics between the two tests showed a value of 0.88. CONCLUSION: Patch tests showed to be reliable for negative, moderately (++) positive and strongly (+++) positive results, by reproducing the same standard of individual response to allergens. However, for weakly (+) positive results, tests were not reliable.

FUNDAMENTOS: Testes de contato positivos, relevantes com a história clínica, identificam os materiais que desencadeiam a dermatite alérgica de contato (DAC). OBJETIVOS: 1)Verificar a persistência ou não de resultados entre testes de contato realizados com intervalo mínimo de um ano, em pacientes com dermatite alérgica de contato; 2)Determinar a persistência de testes de contato positivos de acordo com a sua intensidade (+, ++ ou +++); 3)Avaliar a permanência de sensibilização de acordo com cada substância testada. MÉTODO: Pacientes com diagnóstico prévio de DAC, confirmado por testes de contato realizados entre 2005 e 2008, foram submetidos à realização de novos testes, utilizando a mesma metodologia do anterior, e os dados foram comparados. RESULTADOS: Um total de 1470 resultados dos dois testes realizados em 49 pacientes foi analisado. Os testes negativos mantiveram-se no segundo teste em 96% e 4% passaram a positivo (+), sem apresentar relevância com a história clínica. Nenhum teste negativo no primeiro teste passou para positivo de intensidade (++) ou (+++). Além disso, os testes positivos(++) mantiveram-se em 86% dos testes e, os positivos (+++), em 100%. Já em relação aos testes positivos(+), 65% tornaram-se negativos. Ao se desconsiderar todos os resultados positivos(+), o índice Kappa foi de 0,88, evidenciando concordância excelente entre os dois testes realizados. CONCLUSÕES: Os testes de contato mostraram-se confiáveis para os resultados negativo, positivo (++) e (+++).

Estudio de artículos hipoalergénicos para niños con parche de Schwartz-Peck / Hipoallergenic substances in children. Study with Schwartz-Pech patch

Objetivo: demostrar las características hipoalergénicas de seis artículos de uso común en niños. Diseño: estudio prospectivo, controlado, abierto. Materiales y métodos: 160 niños, de edades comprendidas entre 6 meses y 10 años. Se colocaron parches impregnados con cada una de las sustancias a estudiar, además de un parche control, impregnado con agua. Durante 48 horas los parches estuvieron en contacto con la piel de los niños, efectuándose lecturas de las reacciones provocadas a las 48 y 96 horas. Luego de dos semanas de descanso, cuatro sujetos reaccionaron a las 96 horas, 1 a la sustancia 316 (0,6 por ciento) otro a la sustancia 205 (0.6 por ciento), sin presentar diferencias estadísticamente significativas con respecto a las reacciones encontradas con la aplicación de agua como sustancia control. Conclusión: las sustancias estudiadas no provocaron reacciones de irritación o alergia en forma significativa en la gran mayoría de los niños. Palabras clave: Alergia, irritación, hipoalergénicos, Parche de Schwartz-Peck