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

Antecedentes: El Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea tiene entre sus objetivos la vigilancia epidemiológica de la dermatitis de contacto. Para ello es importante conocer si se producen alteraciones en el tiempo de las prevalencias de las positividades a los distintos alérgenos. Objetivos: Describir las variaciones en las tendencias temporales en positividades a alérgenos en la serie estándar del GEIDAC en el periodo comprendido entre 2018 y el 31 de diciembre de 2022. Métodos: Estudio observacional multicéntrico de pacientes estudiados consecutivamente mediante pruebas epicutáneas dentro del estudio de un posible eczema alérgico de contacto recogidos de forma prospectiva en el seno del Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. Se analizaron los datos mediante 2 pruebas estadísticas: una de homogeneidad (para ver si hay cambios en los diferentes años) y otra de tendencia (para ver si los cambios siguen una tendencia lineal). Resultados: Se incluyeron un total de 11.327 pacientes en el periodo de estudio. Los alérgenos en los que de forma global se detectó una sensibilización mayor fueron sulfato de níquel, metilisotiazolinona, cloruro de cobalto, metilcloroisotiazolinona/metilisotiazolinona y mezcla de fragancias i. Se detectó una disminución estadísticamente significativa en el porcentaje de positividades de metilisotiazolinona a lo largo de años de estudio con una tendencia ordenada. Conclusiones: Si bien se pueden apreciar diferentes cambios en las tendencias a sensibilizaciones a varios de los alérgenos de la batería estándar, se observa que persiste una alta sensibilización al níquel, a la metilcloroisotiazolinona/metilisotiazolinona y a la mezcla de fragancias i. Solo se aprecia una tendencia a disminuir de forma significativa en el caso de la metilisotiazolinona.(AU)

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.(AU)

[Translated article] 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

Antecedentes: El Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea tiene entre sus objetivos la vigilancia epidemiológica de la dermatitis de contacto. Para ello es importante conocer si se producen alteraciones en el tiempo de las prevalencias de las positividades a los distintos alérgenos. Objetivos: Describir las variaciones en las tendencias temporales en positividades a alérgenos en la serie estándar del GEIDAC en el periodo comprendido entre 2018 y el 31 de diciembre de 2022. Métodos: Estudio observacional multicéntrico de pacientes estudiados consecutivamente mediante pruebas epicutáneas dentro del estudio de un posible eczema alérgico de contacto recogidos de forma prospectiva en el seno del Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. Se analizaron los datos mediante 2 pruebas estadísticas: una de homogeneidad (para ver si hay cambios en los diferentes años) y otra de tendencia (para ver si los cambios siguen una tendencia lineal). Resultados: Se incluyeron un total de 11.327 pacientes en el periodo de estudio. Los alérgenos en los que de forma global se detectó una sensibilización mayor fueron sulfato de níquel, metilisotiazolinona, cloruro de cobalto, metilcloroisotiazolinona/metilisotiazolinona y mezcla de fragancias i. Se detectó una disminución estadísticamente significativa en el porcentaje de positividades de metilisotiazolinona a lo largo de años de estudio con una tendencia ordenada. Conclusiones: Si bien se pueden apreciar diferentes cambios en las tendencias a sensibilizaciones a varios de los alérgenos de la batería estándar, se observa que persiste una alta sensibilización al níquel, a la metilcloroisotiazolinona/metilisotiazolinona y a la mezcla de fragancias i. Solo se aprecia una tendencia a disminuir de forma significativa en el caso de la metilisotiazolinona.(AU)

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.(AU)

Standard and Expanded Series Patch Testing Update by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC). / Actualización de la batería estándar y batería ampliada de pruebas alérgicas de contacto por el Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (GEIDAC).

After the meeting held by the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) back in October 2021, changes were suggested to the Spanish standard series patch testing. Hydroxyethyl methacrylate (2% pet.), textile dye mixt (6.6% pet.), linalool hydroperoxide (1% pet.), and limonene hydroperoxide (0.3% pet.) were, then, added to the series that agreed upon in 2016. Ethyldiamine and phenoxyethanol were excluded. Methyldibromoglutaronitrile, the mixture of sesquiterpene lactones, and hydroxyisohexyl 3-cyclohexene (Lyral) were alo added to the extended Spanish series of 2022.

Dispositivos médicos en pacientes diabéticos y dermatitis de contacto / Medical Devices in Patients With Diabetes and Contact Dermatitis

El desarrollo y comercialización de los sensores de glucosa y las bombas de insulina han supuesto una revolución en el control de los pacientes diabéticos. En los últimos años se han detectado múltiples casos de dermatitis de contacto relacionados con estos dispositivos médicos, con el creciente interés sobre los alérgenos responsables de la sensibilización. Isobornil acrilato fue sin duda el alérgeno principal del dispositivo FreeStyle, motivando al fabricante a modificar la composición eliminando este alérgeno. Curiosamente, este alérgeno está presente en casi todos los sensores comercializados. La colofonia y derivados del ácido abiético desempeñan un papel relevante en cuanto al adhesivo. Recientemente aparecen nuevos componentes identificados como alérgenos, no comercializadas, como el dipropilene glicol diacrilato, la N,N-dimetilacrilamida, o el metacrilato de trietilenglicol, que están siendo foco de estudio. El impacto positivo que tiene el uso de estos dispositivos puede verse mermado por la sensibilización a uno de sus ingredientes, obligando en ocasiones a abandonar el dispositivo, y por ende, restando calidad de vida. El dermatólogo debe posicionarse respecto al estudio dirigido de estos pacientes, dando soporte a los servicios de endocrinología, con la finalidad de orientar tanto el cuidado de la piel como las alternativas posibles, especialmente con la colaboración de los fabricantes.(AU)

The development and commercialization of glucose sensors and insulin pumps has revolutionized the management of diabetes. These devices have been linked to multiple cases of contact dermatitis in recent years, however, giving rise to a growing interest in identifying the sensitizing allergens. Isobornyl acrylate was clearly identified as one of the main allergens responsible for contact dermatitis among users of the FreeStyle glucose sensor and was subsequently removed from the product ingredients. Remarkably, however, it is still used in most other sensors on the market. The common adhesive ingredients colophony and abietic acid derivatives have also been shown to be sensitizing agents. New components under study, such as dipropylene glycol diacrylate, N,N-dimethylacrylamide, and triethylene glycol methacrylate have recently been identified as allergens, though they are not commercially available for clinical testing. The benefits offered by glucose sensors and insulin pumps may be offset by sensitization to product ingredients, in some cases forcing discontinuation and diminishing quality of life. Dermatologists should play a role in this clinical and research scenario, offering case-by-case guidance to endocrinologists on skin care and possible alternatives for patients with glucose sensors and insulin pumps who develop contact dermatitis. They should also collaborate with the manufacturers developing these devices.(AU)

[Translated article] Medical Devices in Patients With Diabetes and Contact Dermatitis / Dispositivos médicos en pacientes diabéticos y dermatitis de contacto

El desarrollo y comercialización de los sensores de glucosa y las bombas de insulina han supuesto una revolución en el control de los pacientes diabéticos. En los últimos años se han detectado múltiples casos de dermatitis de contacto relacionados con estos dispositivos médicos, con el creciente interés sobre los alérgenos responsables de la sensibilización. Isobornil acrilato fue sin duda el alérgeno principal del dispositivo FreeStyle, motivando al fabricante a modificar la composición eliminando este alérgeno. Curiosamente, este alérgeno está presente en casi todos los sensores comercializados. La colofonia y derivados del ácido abiético desempeñan un papel relevante en cuanto al adhesivo. Recientemente aparecen nuevos componentes identificados como alérgenos, no comercializadas, como el dipropilene glicol diacrilato, la N,N-dimetilacrilamida, o el metacrilato de trietilenglicol, que están siendo foco de estudio. El impacto positivo que tiene el uso de estos dispositivos puede verse mermado por la sensibilización a uno de sus ingredientes, obligando en ocasiones a abandonar el dispositivo, y por ende, restando calidad de vida. El dermatólogo debe posicionarse respecto al estudio dirigido de estos pacientes, dando soporte a los servicios de endocrinología, con la finalidad de orientar tanto el cuidado de la piel como las alternativas posibles, especialmente con la colaboración de los fabricantes.(AU)

The development and commercialization of glucose sensors and insulin pumps has revolutionized the management of diabetes. These devices have been linked to multiple cases of contact dermatitis in recent years, however, giving rise to a growing interest in identifying the sensitizing allergens. Isobornyl acrylate was clearly identified as one of the main allergens responsible for contact dermatitis among users of the FreeStyle glucose sensor and was subsequently removed from the product ingredients. Remarkably, however, it is still used in most other sensors on the market. The common adhesive ingredients colophony and abietic acid derivatives have also been shown to be sensitizing agents. New components under study, such as dipropylene glycol diacrylate, N,N-dimethylacrylamide, and triethylene glycol methacrylate have recently been identified as allergens, though they are not commercially available for clinical testing. The benefits offered by glucose sensors and insulin pumps may be offset by sensitization to product ingredients, in some cases forcing discontinuation and diminishing quality of life. Dermatologists should play a role in this clinical and research scenario, offering case-by-case guidance to endocrinologists on skin care and possible alternatives for patients with glucose sensors and insulin pumps who develop contact dermatitis. They should also collaborate with the manufacturers developing these devices.(AU)

Epidemiological, Clinical, and Allergic Profile of Psoriatic Patients. Evaluation of the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC). / Perfil epidemiológico, clínico y alérgico en pacientes con psoriasis. Evaluación del Registro Español de Dermatitis de Contacto (REIDAC).

BACKGROUND: Psoriasis is a chronic inflammatory dermatosis whose clinical and topographic distribution requires differential diagnosis, or the possible association with allergic contact dermatitis (ACD), requiring patch testing (PT) as part of the diagnostic procedure. OBJECTIVES: To describe the epidemiological, clinical, and allergic profile of patients with a primary or secondary diagnosis of psoriasis undergoing PT and compare them with patients with a diagnosis of ACD at the end of the diagnostic process. METHODS: Cross-sectional study with data from REIDAC from 2018 through 2023 of selected patients with a diagnosis of psoriasis and/or ACD. RESULTS: A total of 11 502 patients were included, 513 of whom had been diagnosed with primary or secondary psoriasis, 3640 with ACD, and 108 with both diseases. Men were more predominant in the groups of patients with psoriasis, psoriasis+ACD, and lesions were more predominantly seen in the hands with little association with atopic factors vs the ACD group. The rate of positivity in PT to the 2022 Spanish battery of allergens was lower in the group with psoriasis only in 27% of the patients. The most common allergens found in the psoriasis group were also the most common ones found in the overall ACD population. CONCLUSIONS: Overall, 36.2% of psoriatic patients tested positive in PT to the 2022 Spanish battery of allergens, which proved that this association is not uncommon. Overall, psoriatic patients had a higher mean age, were more predominantly men, and showed more hand involvement.

[Translated article] Medical Devices in Patients With Diabetes and Contact Dermatitis.

The development and commercialization of glucose sensors and insulin pumps has revolutionized the management of diabetes. These devices have been linked to multiple cases of contact dermatitis in recent years, however, giving rise to a growing interest in identifying the sensitizing allergens. Isobornyl acrylate was clearly identified as one of the main allergens responsible for contact dermatitis among users of the FreeStyle glucose sensor and was subsequently removed from the product ingredients. Remarkably, however, it is still used in most other sensors on the market. The common adhesive ingredients colophony and abietic acid derivatives have also been shown to be sensitizing agents. New components under study, such as dipropylene glycol diacrylate, N,N-dimethylacrylamide, and triethylene glycol methacrylate have recently been identified as allergens, though they are not commercially available for clinical testing. The benefits offered by glucose sensors and insulin pumps may be offset by sensitization to product ingredients, in some cases forcing discontinuation and diminishing quality of life. Dermatologists should play a role in this clinical and research scenario, offering case-by-case guidance to endocrinologists on skin care and possible alternatives for patients with glucose sensors and insulin pumps who develop contact dermatitis. They should also collaborate with the manufacturers developing these devices.

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.

Contact Allergy to Shellac. Retrospective Cross-Sectional Study With Data From the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy (REIDAC) / Alergia de contacto a shellac. Estudio transversal retrospectivo con datos del Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (REIDAC)

Introduction Shellac is a known allergen present mainly in cosmetics used on the eyelids and lips, although new sources of exposure have recently been described. Our objective was to assess the use of shellac as a contact allergen in Spain and the clinical profile of patients allergic to shellac. Methods This retrospective cross-sectional study included patients patch tested for shellac between 2018 and 2021 from the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC). Results A total of 980 patients were patch tested for shellac (20% in ethanol), and 37 (3.77%, 95% confidence interval [CI], 2.58–3.97%) showed positive results. Most of these patients were tested for shellac due to a suspicion of cosmetic contact dermatitis. Seven patients with present relevance were found, five with relation to cosmetics, and the other two with an occupational background of food handling. The reaction index for shellac was 0.51 and the positivity ratio was 67.56% (95% CI, 52.48–82.65%). Conclusions Shellac appears to be a prevalent allergen in patients with suspected contact dermatitis related with cosmetics or foodstuff. However, further studies are needed to validate its use in other patients (AU)

El shellac es un alérgeno conocido por su presencia en cosméticos para labios y párpados, aunque en los últimos años se han descrito nuevas fuentes de exposición. El objetivo de nuestro trabajo fue evaluar cómo se está usando el shellac, como alérgeno de contacto en España, y las características clínicas de los pacientes alérgicos al shellac. Métodos Se realizó un estudio retrospectivo transversal con los pacientes incluidos en el Registro Español de Dermatitis de Contacto y Alergia Cutánea en los que se realizaron pruebas epicutáneas con shellac desde 2018 a 2021. Resultados El shellac (20% en etanol) fue usado en 980 pacientes, con resultados positivos en 37 de ellos (3,77%; intervalo de confianza [IC] del 95%: 2,58-3,97%). La mayoría de estos pacientes realizaron las pruebas epicutáneas por una sospecha de dermatitis de contacto por cosméticos. Se encontraron 7 pacientes con una relevancia presente, 5 de ellos en relación con el uso de cosméticos, y los otros 2 fueron dermatitis de contacto ocupacionales en el contexto de la manipulación de alimentos. El índice de reacción para el shellac fue del 0,51% y la ratio de positividad del 67,56% (IC 95%: 52,48-82,65%). Conclusiones El shellac parece un alérgeno frecuente en los pacientes con sospecha de dermatitis de contacto por cosméticos o alimentos. Sin embargo, se necesitan más estudios para validar su uso en otros pacientes (AU)

[Artículo traducido] Alergia de contacto a shellac. Estudio transversal retrospectivo con datos del Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (REIDAC) / Contact Allergy to Shellac. Retrospective Cross-Sectional Study With Data From the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy (REIDAC)

El shellac es un alérgeno conocido por su presencia en cosméticos para labios y párpados, aunque en los últimos años se han descrito nuevas fuentes de exposición. El objetivo de nuestro trabajo fue evaluar cómo se está usando el shellac, como alérgeno de contacto en España, y las características clínicas de los pacientes alérgicos al shellac. Métodos Se realizó un estudio retrospectivo transversal con los pacientes incluidos en el Registro Español de Dermatitis de Contacto y Alergia Cutánea en los que se realizaron pruebas epicutáneas con shellac desde 2018 a 2021. Resultados El shellac (20% en etanol) fue usado en 980 pacientes, con resultados positivos en 37 de ellos (3,77%; intervalo de confianza [IC] del 95%: 2,58-3,97%). La mayoría de estos pacientes realizaron las pruebas epicutáneas por una sospecha de dermatitis de contacto por cosméticos. Se encontraron 7 pacientes con una relevancia presente, 5 de ellos en relación con el uso de cosméticos, y los otros 2 fueron dermatitis de contacto ocupacionales en el contexto de la manipulación de alimentos. El índice de reacción para el shellac fue del 0,51% y la ratio de positividad del 67,56% (IC 95%: 52,48-82,65%). Conclusiones El shellac parece un alérgeno frecuente en los pacientes con sospecha de dermatitis de contacto por cosméticos o alimentos. Sin embargo, se necesitan más estudios para validar su uso en otros pacientes (AU)

Introduction Shellac is a known allergen present mainly in cosmetics used on the eyelids and lips, although new sources of exposure have recently been described. Our objective was to assess the use of shellac as a contact allergen in Spain and the clinical profile of patients allergic to shellac. Methods This retrospective cross-sectional study included patients patch tested for shellac between 2018 and 2021 from the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC). Results A total of 980 patients were patch tested for shellac (20% in ethanol), and 37 (3.77%, 95% confidence interval [CI], 2.58–3.97%) showed positive results. Most of these patients were tested for shellac due to a suspicion of cosmetic contact dermatitis. Seven patients with present relevance were found, five with relation to cosmetics, and the other two with an occupational background of food handling. The reaction index for shellac was 0.51 and the positivity ratio was 67.56% (95% CI, 52.48–82.65%). Conclusions Shellac appears to be a prevalent allergen in patients with suspected contact dermatitis related with cosmetics or foodstuff. However, further studies are needed to validate its use in other patients (AU)

Contact Allergy to Shellac. Retrospective Cross-Sectional Study With Data From the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy (REIDAC). / [Artículo traducido] Alergia de contacto a shellac. Estudio transversal retrospectivo con datos del Registro Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (REIDAC).

INTRODUCTION: Shellac is a known allergen present mainly in cosmetics used on the eyelids and lips, although new sources of exposure have recently been described. Our objective was to assess the use of shellac as a contact allergen in Spain and the clinical profile of patients allergic to shellac. METHODS: This retrospective cross-sectional study included patients patch tested for shellac between 2018 and 2021 from the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC). RESULTS: A total of 980 patients were patch tested for shellac (20% in ethanol), and 37 (3.77%, 95% confidence interval [CI], 2.58-3.97%) showed positive results. Most of these patients were tested for shellac due to a suspicion of cosmetic contact dermatitis. Seven patients with present relevance were found, five with relation to cosmetics, and the other two with an occupational background of food handling. The reaction index for shellac was 0.51 and the positivity ratio was 67.56% (95% CI, 52.48-82.65%). CONCLUSIONS: Shellac appears to be a prevalent allergen in patients with suspected contact dermatitis related with cosmetics or foodstuff. However, further studies are needed to validate its use in other patients.

Contact Allergy to Shellac. Retrospective Cross-Sectional Study With Data From the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy (REIDAC).

INTRODUCTION: Shellac is a known allergen present mainly in cosmetics used on the eyelids and lips, although new sources of exposure have recently been described. Our objective was to assess the use of shellac as a contact allergen in Spain and the clinical profile of patients allergic to shellac. METHODS: This retrospective cross-sectional study included patients patch tested for shellac between 2018 and 2021 from the Spanish Registry of Contact Dermatitis and Cutaneous Allergy (REIDAC). RESULTS: A total of 980 patients were patch tested for shellac (20% in ethanol), and 37 (3.77%, 95% confidence interval [CI], 2.58-3.97%) showed positive results. Most of these patients were tested for shellac due to a suspicion of cosmetic contact dermatitis. Seven patients with present relevance were found, five with relation to cosmetics, and the other two with an occupational background of food handling. The reaction index for shellac was 0.51 and the positivity ratio was 67.56% (95% CI, 52.48-82.65%). CONCLUSIONS: Shellac appears to be a prevalent allergen in patients with suspected contact dermatitis related with cosmetics or foodstuff. However, further studies are needed to validate its use in other patients.

Dermoscopy in Patch Testing: How Can It Help? / Uso del dermatoscopio en la lectura de pruebas epicutáneas: ¿qué puede aportar?

Interpreting patch test reactions is not easy. It requires experience and is characterized by high intraobserver and interobserver variability. It can sometimes be truly difficult to discern between a weak allergic reaction and an irritant reaction. A number of recent studies have investigated the dermoscopic features of patch test reactions. Homogeneous erythema is the main feature observed in patients with a positive allergic reaction, although dotted vessels, vesicles, crusts and yellow-orange areas may also provide clues. These features are somewhat similar to those observed in inflammatory conditions, such as eczema. In patients with an irritant reaction, the most common dermoscopic findings are the pore reaction pattern and perifollicular erythema. Dermoscopy could be useful for establishing a diagnosis in the case of doubtful patch test reactions.

Claves diagnósticas en el eccema diseminado: experiencia de una unidad de Dermatitis de Contacto (2003-2019) / Diagnostic keys for disseminated eczema: experience of a Dermatitis Contact unit (2003-2019)

El objetivo de este estudio fue establecer los diagnósticos de los pacientes con eccema diseminado y analizar los alérgenos implicados en el eccema diseminado por dermatitis alérgica de contacto. Para ello, se analizaron los datos de los pacientes con diagnóstico de eccema diseminado/generalizado a los que se les había realizado anamnesis, exploración física y pruebas epicutáneas en una consulta de Dermatitis de Contacto en el periodo 2003-2019. El diagnóstico más frecuente fue dermatitis alérgica de contacto, seguido de dermatitis atópica, eccema asteatósico y eccema gravitacional. Los alérgenos más frecuentemente implicados en dermatitis de contacto alérgica fueron las isotiazolinonas, los medicamentos tópicos, la parafenilendiamina y las fragancias. La dermatitis alérgica de contacto causó casi la mitad de los casos de eccema diseminado. Por ello, consideramos conveniente que los pacientes con eccema diseminado sean valorados en una Unidad de Contacto y se sometan a la realización de pruebas epicutáneas.(AU)

The aim of this study was to establish the diagnoses of patients with disseminated eczema and analyze the allergens involved in disseminated eczema due to allergic contact dermatitis. We analyzed the data from patients with a diagnosis of disseminated / generalized eczema who had undergone anamnesis, physical examination and patch tests in a Contact Dermatitis consultation from 2003 to 2019. Allergic contact dermatitis was the most frequent diagnosis, followed by atopic dermatitis, asteatotic eczema, and gravitational eczema. The allergens most frequently involved in allergic contact dermatitis were isothiazolinones, topical medications, paraphenylenediamine, and fragrances. Allergic contact dermatitis caused almost half of the cases of disseminated eczema. It would be therefore advisable for patients with disseminated eczema to be assessed at a Contact Dermatitis unit and undergo patch tests.