Contact dermatitis caused by a new rubber compound detected in canvas shoes

2-Cyanoethyl dimethyldithiocarbamate, a new contact allergen found in accelerator-free nitrile gloves

BACKGROUND

Allergic contact dermatitis (ACD) from rubber glove usage is usually caused by rubber additives such as the accelerators. However, in analyses of the suspected gloves, ordinary rubber allergens are not always found. Accelerator-free rubber gloves are available, but some patients with accelerator allergy do not tolerate them and might also be patch test positive to them.

OBJECTIVES

To identify and chemically characterize a new allergen, 2-cyanoethyl dimethyldithiocarbamate (CEDMC), in rubber gloves. We describe two patient cases: patient 1 that led us to the identification of CEDMC and patient 2 with occupational ACD caused by CEDMC.

METHODS

The patients were examined with patch testing including baseline and rubber series, and their own rubber gloves. High-performance liquid chromatography (HPLC) was used for chemical analysis of rubber gloves. The allergen was synthesized and identified by nuclear magnetic resonance, mass spectrometry and infrared spectrometry, and tested on patient 2.

RESULTS

CEDMC was identified by HPLC in a nitrile glove associated with hand eczema in patient 1. Patient 2 whose nitrile gloves contained CEDMC was patch test positive to CEDMC.

CONCLUSIONS

CEDMC is a new contact allergen in nitrile gloves and probably forms during vulcanization from residual monomer acrylonitrile and rubber additives.

Shoe Allergens: A Retrospective Analysis of Cross-sectional Data From the North American Contact Dermatitis Group, 2005-2018

BACKGROUND

Shoe contact allergy can be difficult to diagnose and manage.

OBJECTIVE

The aim of the study was to characterize demographics, clinical characteristics, patch test results, and occupational data for the North American Contact Dermatitis Group patients with shoe contact allergy.

METHODS

This is a retrospective study of 33,661 patients, patch tested from 2005 to 2018, with a shoe source, foot as 1 of 3 sites of dermatitis, and final primary diagnosis of allergic contact dermatitis.

RESULTS

Three hundred fifty-two patients met the inclusion criteria. They were more likely to be male (odds ratio = 3.36, confidence interval = 2.71-4.17) and less likely to be older than 40 years (odds ratio = 0.49, confidence interval = 0.40-0.61) compared with others with positive patch test reactions. The most common relevant North American Contact Dermatitis Group screening allergens were potassium dichromate (29.8%), p-tert-butylphenol formaldehyde resin (20.1%), thiuram mix (13.3%), mixed dialkyl thioureas (12.6%), and carba mix (12%). A total of 29.8% (105/352) had positive patch test reactions to supplemental allergens, and 12.2% (43/352) only had reactions to supplemental allergens.

CONCLUSIONS

Shoe contact allergy was more common in younger and male patients. Potassium dichromate and p-tert-butylphenol formaldehyde resin were the top shoe allergens. Testing supplemental allergens, personal care products, and shoe components should be part of a comprehensive evaluation of suspected shoe contact allergy.

Shoe Dermatitis

Shoe dermatitis is a type of contact dermatitis precipitated by allergens or irritants found in shoes. Potassium dichromate, commonly used in leather processing, is one of the most prevalent agents responsible for shoe dermatitis; however, it is not the only one. Shoe dermatitis caused by an allergen or an irritant may affect a person of any age, sex, or ethnicity. Numerous treatments exist for shoe dermatitis, the most simple yet important being avoidance of causative agents. Pharmaceutical agents commonly used are emollients, humectants, and topical corticosteroids. In more severe cases, topical calcineurin inhibitors and phototherapy may be used.

The Value of Patch Testing With Shoe Material Samples in Patients Suspected of Shoe Allergic Contact Dermatitis

BACKGROUND

Patch testing is the standard diagnostic tool for shoe allergic contact dermatitis (ACD). As shoe materials change over time, utilizing commercial allergen series might be ineffective. However, because testing with patients' shoe samples is laborious, its value is questioned.

OBJECTIVE

The aim of this study was to ascertain the benefits of patch testing with patients' shoes by comparing the frequencies of patch-test positivity of shoes and shoe-related allergens in baseline series for suspected shoe ACD patients.

METHODS

A retrospective study was conducted of patients with clinically suspected shoe ACD who underwent patch testing with baseline series and shoe samples 2000 to 2019.

RESULTS

Almost half of the cohort (77 of 178; 43.3%) was diagnosed with shoe ACD. Of those 77, 48 (62.3%) were positive to shoe-related allergens from the baseline series, whereas 53 (68.8%) were positive to their shoe materials. The prevalence of tests positive to shoe material but negative to shoe-related allergens was 29 of 77 (37.7%). The most common shoe-related allergens were potassium dichromate (7.9%), carba mix (6.8%), and mercapto mix (6.7%).

CONCLUSIONS

Patch testing with shoe materials increased the diagnostic yield by 37.7 percent. To diagnose shoe ACD, testing of shoe materials may compensate for unknown, scarce, or novel allergens not in the baseline series.

Patch test results in patients with suspected contact allergy to shoes: Retrospective IVDK data analysis 2009-2018

BACKGROUND

Allergic contact dermatitis caused by shoes is common and new relevant allergens have been identified.

OBJECTIVES

To investigate the pattern of type IV sensitization in patients with suspected allergic contact dermatitis of the feet related to shoes as a presumed culprit trigger.

METHODS

Retrospective analysis of data of the Information Network of Departments of Dermatology (IVDK), 2009-2018.

RESULTS

Six hundred twenty-five patients with presumed shoe dermatitis were identified in a cohort of 119 417 patients. Compared to patients with suspected contact sensitization from other allergen sources (n = 118 792), study group patients were more frequently sensitized to potassium dichromate (10.8% vs 3.5%), colophony (7.2% vs 3.7%), mercaptobenzothiazole (MBT; 4.0% vs 0.6%), mercapto mix (4.6% vs 0.6%), and p-tert-butylphenol formaldehyde resin (1.6% vs 0.5%). Sensitizations to urea formaldehyde resin, melamine formaldehyde resin, glutaraldehyde, tricresyl phosphate, and phenyl glycidylether were rare. Moreover, reactions to compounds in the leather or textile dyes test series were scarce.

CONCLUSION

A distinct sensitization pattern was observed in patients with suspected allergy to shoe materials. Although substances with low sensitization rates should be removed from the leather and shoe patch test series, novel potential allergens should be added.

Contact Allergy-Emerging Allergens and Public Health Impact

Contact allergy (sensitisation) and allergic contact dermatitis (ACD) resulting from it have a considerable public health impact. For the present review, all pertinent articles were systematically searched via Medline and Web of Science™; additionally, all available issues of the journals "Contact Dermatitis" and "Dermatitis" were manually searched, covering the years 2018-2019, thereby extending and re-focusing a previous similar review. New allergens, or previously described allergens found in a new exposure context or of other current importance, are described in sections according to substance classes, e.g., metals, preservatives, fragrances. As a common finding in many investigations, a lack of information on product composition has been noted, for instance, regarding a newly described allergen in canvas shoes (dimethylthiocarbamylbenzothiazole sulfide) and, most notably, absence of co-operation from manufacturers of glucose-monitoring devices and insulin pumps, respectively. These latter devices have been shown to cause severe ACD in a considerable number of diabetic patients caused by the liberation of isobornyl acrylate and N,N'-dimethylacrylamide, respectively, as demonstrated by an international collaboration between dermatologists and chemists. Improved and complete ingredient labelling for all types of products, and not just cosmetics, must be put on the legislative agenda.

In vitro assessment of mechanistic events induced by structurally related chemical rubber sensitizers

Allergic contact dermatitis (ACD) is one of the most common forms of immunotoxicity, and increased understanding of how chemicals trigger these adverse reactions is needed in order to treat or design testing strategies to identify and subsequently avoid exposure to such substances. In this study, we investigated the cellular response induced by rubber chemicals in a dendritic cell (DC) model, focusing on the structurally similar chemicals diethylthiocarbamylbenzothiazole sulfide and dimethylthiocarbamylbenzothiazole sulfide, with regard to regulation of microRNA, and messenger RNA expression. Only a few miRNAs were found to be commonly regulated by both rubber chemicals, among them miR1973, while the overall miRNA expression profiles were diverse. Similarly, out of approximately 500 differentially regulated transcripts for each chemical, about 60% overlapped, while remaining were unique. The pathways predicted to be enriched in the cell model by stimulation with the rubber chemicals were linked to immunological events, relevant in the context of ACD. These results suggest that small structural differences can trigger specific activation of the immune system in response to chemicals. The here presented mechanistic data can be valuable in explaining the immunotoxicological events in DC activation after exposure to skin sensitizing chemicals, and can contribute to understanding, preventing and treating ACD.