Patch Testing in Allergic Contact Dermatitis.

BACKGROUND: Allergic contact dermatitis is one of the most common forms of skin diseases that require medical intervention. Appropriate detection of allergens by patch test and accurate avoidance of them is the key to management. The objective of this study is to determine the types and frequency of allergens responsible for Allergic contact dermatitis in a tertiary hospital of Nepal. METHODS: Altogether 120 patients with Allergic contact dermatitis were enrolled in the study. Patch test was performed to find out the most common inciting allergen, utilizing the Indian Standard Series of allergens approved by The Contact and Occupational Dermatoses Forum of India. Results were read at 48 and 96 hours. Grading of the reactions was done based on the criteria of the International Contact Dermatitis Research Group. Pattern of reactivity of different allergens was assessed. RESULTS: Of all the patients, 63 (53%) showed positivity to at least one allergen. Nickel sulfate was the most frequent sensitizing agent in 22 (18%) cases, followed by Fragrance mix in 11(9%) and Paraphenylenediamine in 7 (6%) cases. Out of all positive results, Grade 1 positivity was seen in 44 (51%), Grade 2 positivity in 41(47%) and only 2 (2%) cases showed Grade 3 positivity. Mercaptobenzothiazole, Balsam of Peru, Nitrofurazone and Wool Alcohol did not show positive results in any of our patients. CONCLUSIONS: Patch testing helps in the treatment, long term remission, and patient counseling for prevention. Larger scale studies are required to know the sensitivity to allergens in Nepalese population.

Occurrence of alkyl glucosides in rinse-off cosmetics marketed as hypoallergenic or for sensitive skin.

Rinse-off cosmetic products, primarily shampoos, are frequently implicated in the onset of allergic contact dermatitis (ACD) caused by alkyl glucosides (AGs). AGs are increasingly popular surfactants and known contact allergens. Glucoside-induced ACD was most frequently observed with shampoos and skin-cleansing products in both consumer and occupational settings. Thereby, studies have shown that atopic individuals are the most susceptible to ACD. Also, several investigations have indicated that individuals with sensitive skin might be more prone to skin allergies. This is why the presence of AGs was investigated in shampoos and body cleansers marketed as hypoallergenic or for sensitive skin. For this purpose, the website of Amazon.com was surveyed. Four groups of cosmetics were obtained by using the following keywords: "hypoallergenic shampoo for adults," "sensitive skin shampoo for adults," "hypoallergenic body cleanser for adults," and "sensitive skin body cleanser for adults." The first 30 best-selling cosmetics in each group were investigated for the presence of AGs, by analyzing the product information pages. The results showed that as much as 56.7% of hypoallergenic shampoos contained AGs, as ingredients, whereas the percentage was somewhat lower for other product categories. Even though decyl and lauryl glucoside were nearly ubiquitously used AGs in cosmetics over the past decade, the most commonly present AG in our analysis was coco-glucoside. The results of this study indicated a necessity to include coco-glucoside in the baseline series of patch testing allergens. Industry, regulators, and healthcare providers should be made aware of the frequent presence of AGs in rinse-off cosmetic products marketed as hypoallergenic or for sensitive skin to ensure the safety and well-being of consumers and patients.

The new Italian SIDAPA Baseline Series for patch testing (2023): an update according to the new regulatory pathway for contact allergens.

Allergic contact dermatitis (ACD) is a common inflammatory skin disease caused by delayed hypersensitivity to chemical and biotic contact allergens. ACD significantly affects the patients' quality of life negatively impacting both occupational and non-occupational settings. Patch testing is the gold standard diagnostic in vivo test to precise the ACD etiology and to correctly perform prevention. According to the Italian Medicines Agency (AIFA) legislative decree no. 178 of 29th May 1991, allergens are defined as medicines and therefore they are subject to strict regulation. In 2017, AIFA (decree no. 2130/2017) started a procedure to regulate contact allergens on the Italian market and actually the contact allergens temporarily authorized are reported in AIFA decree no. 98/2022, valid until November 2023. The availability on the market of contact allergens to diagnose ACD and continuous updating on the basis of new epidemiological trends are mandatory, jointly with the continuous update of the baseline and integrative series for patch testing. For this reason, the scientific community represented in Italy by the Skin Allergies Study Group of SIDeMaST (Italian Society of Dermatology and Venereology) and SIDAPA (Italian Society of Allergological, Occupational and Environmental Dermatology) are constantly working, in close relationship with the European scientific communities with large expertise in this important sector of the modern Dermatology. Herein, we report the setting up of regulatory legislation by AIFA and the new Italian Adult Baseline Series for patch testing.

Use of human predictive patch test (HPPT) data for the classification of skin sensitization hazard and potency.

Since the 1940s, patch tests in healthy volunteers (Human Predictive Patch Tests, HPPTs) have been used to identify chemicals that cause skin sensitization in humans. Recently, we reported the results of a major curation effort to support the development of OECD Guideline 497 on Defined Approaches (DAs) for skin sensitization (OECD in Guideline No. 497: Defined Approaches on Skin Sensitisation, 2021a. https://doi.org/10.1787/b92879a4-en ). In the course of this work, we compiled and published a database of 2277 HPPT results for 1366 unique test substances (Strickland et al. in Arch Toxicol 97:2825-2837, 2023. https://doi.org/10.1007/s00204-023-03530-3 ). Here we report a detailed analysis of the value of HPPT data for classification of chemicals as skin sensitizers under the United Nations' Globally Harmonized System of Classification and Labelling of Chemicals (GHS). As a result, we propose the dose per skin area (DSA) used for classification by the GHS to be replaced by or complemented with a dose descriptor that may better reflect sensitization incidence [e.g., the DSA causing induction of sensitization in one individual (DSA1+) or the DSA leading to an incidence of induction in 5% of the tested individuals (DSA05)]. We also propose standardized concepts and workflows for assessing individual HPPT results, for integrating multiple HPPT results and for using them in concert with Local Lymph Node Assay (LLNA) data in a weight of evidence (WoE) assessment. Overall, our findings show that HPPT results are often not sufficient for deriving unambiguous classifications on their own. However, where they are, the resulting classifications are reliable and reproducible and can be integrated well with those from other skin sensitization data, such as the LLNA.

Contact Allergy to Allergens in the Swedish Baseline Series Overrepresented in Diabetes Patients with Skin Reactions to Medical Devices - A Retrospective Study from Southern Sweden.

Allergic contact dermatitis is reported among individuals using continuous glucose monitoring systems and insulin pumps. The aim of this study was to describe contact allergy patterns for allergens in the Swedish baseline series and medical device-related allergens among users. Contact allergy to baseline series allergens and isobornyl acrylate was compared between diabetes patients and dermatitis patients patch-tested at the Department of Occupational and Environmental Dermatology during 2017 to 2020. Fifty- four diabetes patients and 2,567 dermatitis patients were included. The prevalence of contact allergy to fragrance mix II and sesquiterpene lactone mix was significantly higher in diabetes patients compared with dermatitis patients. Of the diabetes patients 13.0% and of the dermatitis patients 0.5% tested positive to sesquiterpene lactone mix (p < 0.001). Of the diabetes patients 7.4% and of the dermatitis patients 2.3% tested positive to fragrance mix II (p = 0.041). Of the diabetes patients 70.4% tested positive to medical device-related allergens. Of the diabetes patients 63.0% and of the dermatitis patients 0.2% were allergic to isobornyl acrylate (p < 0.001). In conclusion, not only medical device-related contact allergies, but also contact allergy to baseline series allergens (fragrance mix II and sesquiterpene lactone mix), is overrepresented in diabetes patients who use medical devices.

Neutrophil-derived oxidative stress contributes to skin inflammation and scratching in a mouse model of allergic contact dermatitis via triggering pro-inflammatory cytokine and pruritogen production in skin.

Allergic contact dermatitis (ACD) is a common skin disease featured with skin inflammation and a mixed itch/pain sensation. The itch/pain causes the desire to scratch, affecting both physical and psychological aspects of patients. Nevertheless, the mechanisms underlying itch/pain sensation of ACD still remain elusive. Here, we found that oxidative stress and oxidation-related injury were remarkably increased in the inflamed skin of a mouse model of ACD. Reducing oxidative stress significantly attenuated itch/pain-related scratching, allokonesis and skin inflammation. RNA-Sequencing reveals oxidative stress contributes to a series of skin biological processes, including inflammation and immune response. Attenuating oxidative stress reduces overproduction of IL-1ß and IL-33, two critical cytokines involved in inflammation and pain/itch, in the inflamed skin of model mice. Exogenously injecting H2O2 into the neck skin of naïve mice triggered IL-33 overproduction in skin keratinocytes and induced scratching, which was reduced in mice deficient in IL-33 receptor ST2. ACD model mice showed remarkable neutrophil infiltration in the inflamed skin. Blocking neutrophil infiltration reduced oxidative stress and attenuated scratching and skin inflammation. Therefore, our study reveals a critical contribution of neutrophil-derived oxidative stress to skin inflammation and itch/pain-related scratching of ACD model mice via mechanisms involving the triggering of IL-33 overproduction in skin keratinocytes. Targeting skin oxidative stress may represent an effective therapy for ameliorating ACD.

GARD™skin and GARD™potency: A proof-of-concept study investigating applicability domain for agrochemical formulations.

Several New Approach Methodologies (NAMs) for hazard assessment of skin sensitisers have been formally validated. However, data regarding their applicability on certain product classes are limited. The purpose of this project was to provide initial evidence on the applicability domain of GARD™skin and GARD™potency for the product class of agrochemical formulations. For this proof of concept, 30 liquid and 12 solid agrochemical formulations were tested in GARDskin for hazard predictions. Formulations predicted as sensitisers were further evaluated in the GARDpotency assay to determine GHS skin sensitisation category. The selected formulations were of product types, efficacy groups and sensitisation hazard classes representative of the industry's products. The performance of GARDskin was estimated by comparing results to existing in vivo animal data. The overall accuracy, sensitivity, and specificity were 76.2% (32/42), 85.0% (17/20), and 68.2% (15/22), respectively, with the predictivity for liquid formulations being slightly higher compared to the solid formulations. GARDpotency correctly subcategorized 14 out of the 17 correctly predicted sensitisers. Lack of concordance was justifiable by compositional or borderline response analysis. In conclusion, GARDskin and GARDpotency showed satisfactory performance in this initial proof-of-concept study, which supports consideration of agrochemical formulations being within the applicability domain of the test methods.

Effect of Bacillus subtilis and Bacillus coagulans spores on induced allergic contact dermatitis in dogs.

BACKGROUND: Probiotic strains have the potential to modulate immune responses, reduce intestinal inflammation, normalize intestinal mucosal function and decrease allergic reactions. OBJECTIVE: This study aimed to investigate the effect of oral probiotic supplements containing Bacillus subtilis and Bacillus coagulans spores on clinical symptoms, haematological factors and immune responses to allergic contact dermatitis in dogs induced by dinitrochlorobenzene (DNCB). METHODS: DNCB was injected subcutaneously into the scapular region of 20 healthy adult dogs of both sexes, divided into four groups, to induce experimental allergic contact dermatitis. Dogs in Group 1 received food without probiotics or medication. Oral prednisolone was administered to Group 2 for 30 days at a dosage of 0.25 mg/kg every other day. The dogs in Group 3 were treated with a combination of oral prednisolone and probiotics. The dogs in Group 4 were fed daily with a mixture of 109 B. subtilis and B. coagulans bacteria for 30 days. The immune system responses and related gene expression were analysed in the treated animals. RESULTS: The administration of probiotics for 30 days resulted in a reduction in clinical symptoms and duration of wound repair. The probiotics treatment also significantly increased the serum bactericidal effects against Staphylococcus aureus and Escherichia coli. It enhanced both the classic and alternative activity of the complement, as well as lysozyme activity. Additionally, the probiotics led to higher total immunoglobulin levels and significant reductions in anti-trypsin and C-reactive protein levels. Furthermore, the expression of IgE, induction of interferon-gamma and IL-4 genes were also reduced. CONCLUSIONS: According to the results, B. subtilis and B. coagulans can be further investigated as a viable alternative to corticosteroids in treating allergic contact dermatitis in dogs.

Effect of smoking on the clinical and allergological profile of contact dermatitis.

INTRODUCTION: Several clinical and epidemiological data point to a possible link between smoking exposure and contact dermatitis (CD). AIMS: To identify the clinical and epidemiological differences of CD in smoking and non-smoking subjects, and to determine the influence of smoking on the allergological profile of CD. METHODS: Retrospective descriptive study who consulted the Department of Occupational Medicine and Occupational Pathology of the Farhat Hached University Hospital of Sousse (Tunisia) during a period of 8 years for exploration of CD and who were tested with the European Standard Battery (ESB). RESULTS: A total of 767 patients were enrolled during the study period, 40% of whom were smokers. The group of smokers was characterized by a male predominance (p=10-3) and a greater professional seniority compared to non-smokers (p=0.01). Personal history of atopy was predominant in non-smokers (p=0.02). Among the ESB allergens, there was a significant association between smoking and CD due to metals (chromium, cobalt) and conservatives. After binary logistic regression, the variables associated with smoking exposure were male gender (OR=12.12 ; 95% CI=[6.07 - 24.21]; p=10-3), Kathon CG allergy (OR=3.69 ; 95% CI=[1.24 - 10.81]; p=0.018), and right hand involvement (OR= 2.83; 95% CI=[1.29 - 6.17]; p=0.005). CONCLUSION: Our study revealed an effect of smoking on the clinical and allergological characteristics of CD.

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)

Axillary Contact Dermatitis: An Update on Potential Allergens and Management.

The differential diagnosis of dermatoses in the axillae is broad. Contact dermatitis-both irritant and allergic-represents common etiologies. Axillary contact dermatitis can develop following exposure to a variety of irritants and/or allergens. Frequently implicated sources include deodorants, antiperspirants, detergents, soaps, and clothing. Fragrance, a ubiquitous ingredient within these products, as well as metals and dyes, are common causes of contact dermatitis. Clinical assessment, bedside diagnostic techniques, histopathology, and patch testing can aid in the diagnosis and help inform management directions.

Botanical Briefs: Contact Dermatitis Induced by Western Poison Ivy (Toxicodendron rydbergii).

"Leaves of three, leave it be" serves as an apt caution for avoiding poison ivy (Toxicodendron species) and its dermatitis-inducing sap. Toxicodendron contact dermatitis (TCD) poses a notable burden to the American health care system by accounting for half a million reported cases of allergic contact dermatitis (ACD) annually. Identifying and avoiding physical contact with the western poison ivy (Toxicodendron rydbergii) plant prevails as the chief method of preventing TCD. This article discusses common features of T rydbergii as well as clinical manifestations and treatment options following exposure to this allergenic plant.

Contact allergy to topical corticosteroids.

Topical corticosteroids are commonly used to treat inflammatory skin conditions due to their anti-inflammatory properties. However, patients with long-lasting, non-responsive eczema have to be evaluated for a complicating contact allergy to the topical product. Clinical management of allergic contact dermatitis to corticosteroids can be challenging. The preventive measures should be tailored according to the sensitization patterns and supported by currently available classification systems to avoid cross-reactivity, as argued in this review.

2-Hydroxyethyl methacrylate (2-HEMA) sensitization, a global epidemic at its peak in Spain?

BACKGROUND: A global epidemic of allergic contact dermatitis to (meth)acrylates has been described in relation to the widespread use of manicure products. OBJECTIVES: To evaluate the frequency of sensitization to 2-hydroxyethyl methacrylate (2-HEMA) among consecutively patch tested patients with eczema in Spain; the percentage of current relevance; the MOAHLFA index; and, the potential sources of exposure to (meth)acrylates. METHODS: From January 2019 to December 2022, 2-HEMA 2% pet. was prospectively patch tested in 24 REIDAC (Spanish Allergic Contact Dermatitis Registry) centres. RESULTS: Six thousand one hundred thirty-four patients were consecutively patch tested with 2-HEMA 2% pet. 265/6134 (4.3%) were positive. Positive reactions of current relevance were identified to involve 184/265 (69%). The efficiency (number of patch tests needed to detect relevant positive patch test reactions) was 34 (6134/184). The variable 'occupational' was found to be significantly associated with a higher risk for relevant positive reactions to 2-HEMA (OR: 10.9; 95% CI: 8.1-14.9). CONCLUSION: (Meth)acrylate sensitization is a prevalent health issue in Spain. 2-HEMA 2% pet. has been identified to be a highly effective (meth)acrylate allergy marker in the GEIDAC baseline series. The responsible authorities should implement policies guaranteeing accurate labelling of industrial, medical, and consumer materials while ensuring the enforcement of said labelling through appropriate legal means.