Positive Patch Test Reactions to Carba Mix and Thiuram Mix: The North American Contact Dermatitis Group Experience (1994-2016)

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.

Acute health symptoms related to perception and practice of pesticides use among farmers from all regions of Thailand

Introduction

Occupational exposure to pesticides may cause acute health effects for farmers and agricultural workers. Therefore, this study aims to investigate the prevalence of poisoning symptoms related pesticide exposure among farmers from all regions of Thailand, as well as factors linked to poisoning symptoms of neurological and neuromuscular systems, the respiratory system, and eye and skin disorders.

Methods

A cross sectional study was conducted in 4,035 farmers who lived in four regions of Thailand. The samples were chosen using stratified random sampling, with 746 for the Central region, 2,065 for the North-East, 586 for the North, and 638 for the South.

Results

The results found that the highest prevalence of poisoning symptoms was found in association with neurological and neuromuscular systems (75%), followed by the respiratory system (60.4%), the eyes (41.2%), and skin (14.8%). The most prevalent symptoms were muscle pain (49%) for neurological and neuromuscular symptoms, burning nose (37.6%) for respiratory symptoms, itchy eyes (26.3%) for eye symptoms, and rashes (14.4%) for skin symptoms. The remarkable findings were that types of pesticide use, task on the farm, types of pesticide sprayers, and perception are the crucial factors affecting all poisoning symptoms.

Discussion

The findings are also beneficial to the Thai government and other relevant organizations for launching measures, campaigns, or interventions to lower modifiable risk factors, resulting in reducing health risks associated with pesticide exposure.

Prevalence of allergic contact dermatitis in children with and without atopic dermatitis: A multicenter retrospective case-control study

BACKGROUND

As both allergic contact dermatitis and atopic dermatitis (AD) have similar clinical presentations and are characterized by spongiotic dermatitis on skin biopsy, many children with AD are not referred for patch testing and allergic contact dermatitis is underdiagnosed.

OBJECTIVE

To provide updated prevalence data of common contact allergens in children with and without AD.

METHODS

This is a retrospective case-control study using the Pediatric Allergic Contact Dermatitis Registry from 2018 to 2022.

RESULTS

A total of 912 children were included (615 with AD and 297 without AD). Children with AD were more likely to have a longer history of dermatitis (4.1 vs 1.6 years, P < .0001), have seen more providers (2.3 vs 2.1, P = .003), have greater than 1 positive patch test (PPT) result (P = .005), have a greater number of PPT results overall (2.3 vs 1.9, P = .012), and have a more generalized distribution of dermatitis (P = .001). PPT to bacitracin (P = .030), carba mix (P = .025), and cocamidopropyl betaine (P = .0007) were significantly increased in children with AD compared to those without AD.

LIMITATIONS

Technical variation between providers and potential for misclassification, selection, and recall biases.

CONCLUSION

Children with AD are significantly more likely to have PPT reactions and should be referred for evaluation of allergic contact dermatitis and obtain patch testing.

Systematic Identification of Copositivity Groups in Standard Series Patch Testing Through Hierarchical Clustering

Importance

Patients are frequently copositive for multiple allergens simultaneously, either due to chemical similarity or simultaneous sensitization. A better understanding of copositivity groups would help guide contact avoidance.

Objective

To use patient data to systematically determine copositivity groups in the Mayo Clinic Standard Series.

Design, Setting, and Participants

In this retrospective cross-sectional analysis, the Mayo Clinic patch test database was queried for pairwise copositivity rates in the 80 allergen Mayo Clinic Standard Series between 2012 and 2021. Data were collected from 3 tertiary care sites of the Mayo Clinic Contact Dermatitis Group and a total of 5943 patients were included, comprising all patients undergoing patch testing to the Mayo Clinic Standard Series allergens.

Main Outcomes and Measures

Copositivity rates between every 2 allergens in the 80-allergen Mayo Clinic Standard Series were estimated. After background correction, copositivity rates were analyzed using unsupervised hierarchical clustering to systematically identify copositivity groups in an unbiased manner.

Results

Overall, 394 921 total patches were applied to 5943 patients (4164 [70.1%] women, 1776 [29.9%] men, with a mean [SD] age of 52.3 [18.8] years ), comprising 9545 positive reactions. After background correction based on overall positivity rates, hierarchical clustering revealed distinct copositivity groups. Many were supported by prior literature, including formaldehyde releasers, cobalt-nickel-potassium dichromate, acrylates, 3-dimethylaminopropylamine-amidoamine-oleamidopropyl dimethylamine, alkyl glucosides, budesonide-hydrocortisone-17-butyrate, certain fragrances, compositae-sesquiterpene lactone mix, mercapto mix-mercaptobenzothiazole, carba mix-thiuram mix, and disperse orange-p-phenylenediamine. However, novel associations were also found, including glutaraldehyde-sorbitan sesquioleate, benzalkonium chloride-neomycin-bacitracin, bronopol-methylchloroisothiazolinone-methylisothiazolinone, and benzoic acid-iodopropynyl butylcarbamate.

Conclusions and Relevance

This retrospective cross-sectional analysis found that copositivity rates varied between allergens; allergens with extremely high positivity rates demonstrated nonspecific copositivity to multiple other allergens. Background correction based on positivity rates followed by hierarchical clustering confirmed prior known copositivity groups, contaminants and/or excipients leading to copositivity, and novel associations to guide contact avoidance.

Occupational contact allergy: The European perspective-Analysis of patch test data from ESSCA between 2011 and 2020

BACKGROUND

Occupational skin diseases have led the occupational disease statistics in Europe for many years. Especially occupational allergic contact dermatitis is associated with a poor prognosis and low healing rates leading to an enormous burden for the affected individual and for society.

OBJECTIVES

To present the sensitization frequencies to the most relevant allergens of the European baseline series in patients with occupational contact dermatitis (OCD) and to compare sensitization profiles of different occupations.

METHODS

The data of 16 022 patients considered having OCD after patch testing within the European Surveillance System on Contact Allergies (ESSCA) network between January 2011 and December 2020 were evaluated. Patients (n = 46 652) in whom an occupational causation was refuted served as comparison group.

RESULTS

The highest percentages of OCD were found among patients working in agriculture, fishery and related workers, metal industry, chemical industry, followed by building and construction industry, health care, food and service industry. Sensitizations to rubber chemicals (thiurams, carbamates, benzothiazoles) and epoxy resins were associated with at least a doubled risk of OCD. After a decline from 2014 onwards, the risks to acquire an occupation-related sensitization to methyl(chloro)isothiazolinone (MCI/MI) and especially to methylisothiazolinone (MI) seem to increase again. Sensitization rates to formaldehyde were stable, and to methyldibromo glutaronitrile (MDBGN) slightly decreasing over time.

CONCLUSIONS

Among allergens in the European Baseline Series, occupational relevance is most frequently attributed to rubber accelerators, epoxy resins and preservatives.

Occupational Hand Dermatitis

PURPOSE OF REVIEW

Occupational hand dermatitis is a common work-related disorder of the skin. Prevention and management of this disease is critical to improving workers' quality of life and for occupation-specific retention.

RECENT FINDINGS

This is a critical review of the current literature on occupational hand dermatitis. Occupational dermatitis continues to have a high prevalence among workers although the overall incidence may be slowly decreasing. Irritant contact dermatitis due to wet work exposure is the most common cause of occupational hand dermatitis. Healthcare workers, hairdressers, and metal workers are at particularly high risk for this disease. While some prevention programs have been ineffective in mitigating occupational hand dermatitis, other more resource-intensive initiatives may have benefit. Continued research is needed on ways to manage wet work exposures and on scalable, effective prevention programs for occupational hand dermatitis. The spectrum of culprit contact allergens continues to evolve, and vigilance for potential occupation-specific allergens remains important.

Contact allergens for the allergist

OBJECTIVE

The objective of this article is to provide an overview and describe typically encountered skin contact allergens implicated in allergic contact dermatitis (ACD).

DATA SOURCES

Published literature obtained through textbooks, online PubMed, and Google Scholar database searches, author photography, and adapted figures were used.

STUDY SELECTIONS

Studies on the evaluation of ACD and specific skin contact allergens were selected, with a focus on original research articles and clinical reviews.

RESULTS

Major classifications of common contact allergens include the following: (1) fragrances, (2) preservatives, (3) excipients, (4) rubber chemicals, (5) textile dyes, (6) topical medications, and (6) metals and other biomedical device components. The dermatitis distribution can aid in identifying the suspected contact allergen culprit. Certain contact allergens have features that are important to consider in the patch testing (PT) interpretation; these include possible irritant reactions, false-negative reactions or missed detection, and delayed reactions. Fragrances, preservatives, and excipients are culprits in personal products and facial or neck dermatitis. Patch testing with fragrances, preservatives, and patient-supplied products requires careful interpretation. Hand or foot dermatitis may be attributed to rubber chemicals or textile dyes. The management of topical corticosteroid contact allergy is guided on the basis of structural group classifications. Metal sensitization has been associated with dermatitis or biomedical device complications.

CONCLUSION

Each skin contact allergen has unique characteristics with regard to the dermatitis clinical presentation and potential PT nuances. These features are critical to recognize in the evaluation of ACD and PT interpretation and clinical relevance, leading to an accurate diagnosis.

Occupational Contact Dermatitis in Dental Personnel: A Retrospective Analysis of the North American Contact Dermatitis Group Data, 2001 to 2018

BACKGROUND

Dental personnel are at risk of developing occupational contact dermatitis.

OBJECTIVES

The aims of the study were to determine prevalence of occupational contact dermatitis in dental personnel referred for patch testing and to characterize relevant allergens and sources.

METHODS

The study used a retrospective, cross-sectional analysis of the North American Contact Dermatitis Group (NACDG) data, 2001-2018.

RESULTS

Of 41,109 patients, 585 (1.4%) were dental personnel. Dental personnel were significantly more likely than nondental personnel to be female (75.7% vs 67.4%, P < 0.0001), have occupationally related dermatitis (35.7% vs 11.5%, P < 0.0001), and/or have primary hand involvement (48.6% vs 22.5%, P < 0.0001). More than one quarter of dental personnel (62/585, 27.7%) had 1 or more occupationally related allergic patch test reaction(s). There were 249 occupationally related reactions to NACDG screening allergens, most commonly glutaraldehyde (18.1%), thiuram mix (16.1%), and carba mix (14.1%). The most common sources of NACDG screening allergens were gloves (30.7%), dental materials (26.6%), and sterilizing solutions (13.1%). Seventy-three dental personnel (12.5%) had 1 or more positive patch test reactions to occupationally related allergen(s)/substances not on the screening series. Occupationally related irritant contact dermatitis was identified in 22.2% (n = 130) of dental personnel, most commonly to nonskin soaps/detergents/disinfectants (32.0%).

CONCLUSIONS

Occupational contact dermatitis is common in dental personnel referred for patch testing. Comprehensive testing beyond screening series is important in these patients.