Sensitization to 1,3-diphenylguanidine: An underestimated problem in physicians and nurses using surgical gloves?

Quaternary ammoniums activate human dendritic cells and induce a specific T-cell response in vitro

BACKGROUND

In many countries, neuro-muscular blocking agents (NMBAs) are the first cause of perioperative anaphylaxis. Epidemiological studies identified pholcodine, a quaternary ammonium-containing opiate as one of the sensitization sources. However, NMBA anaphylaxis exists in countries where pholcodine was unavailable, prompting the hypothesis of other sensitizing molecules, most likely quaternary ammonium compounds (QACs). Indeed, QACs are commonly used as disinfectants, antiseptics, preservatives, and detergents. Occupational exposure to QACs has been reported as a risk factor for NMBA anaphylaxis, but little is known about the sensitization mechanism and the capacity of these molecules to elicit an immune response. We aimed to establish the immunogenicity of QACs representative of the main existing chemical structures.

METHODS

We measured the sensitization potential of seven QACs (two polyquaterniums, three alkyl-ammoniums and two aromatic ammoniums) by using two standard dendritic cells (DCs) models (THP-1 cell line and monocyte derived-dendritic cells). The allergenicity of the sensitizing compounds was further tested in heterologous and autologous T-cell-DC co-culture models.

RESULTS

Amongst the seven molecules tested, four could modulate activation markers on DCs, and thus can be classified as chemical sensitizers (polyquaterniums-7 and -10, ethylhexadecyldimethylammonium and benzethonium). This activation was accompanied by the secretion of pro-inflammatory and maturation cytokines. Furthermore, activation by polyquaternium-7 could induce T-cell proliferation in heterologous and autologous coculture models, demonstrating that this molecule can induce a specific CD4+ T cell response.

CONCLUSIONS

We provide evidence at the cellular level that some QACs can elicit an immune response, which could be in line with the hypothesis of these molecules' role in NMBA sensitization.

New causes of occupational allergic contact dermatitis

PURPOSE OF REVIEW

Occupational allergic contact dermatitis (OACD) is an important work-related skin disease. Information about the causative agents comes from many sources, including patch test databases, registries, case series and case reports. This review summarizes new information about common causative allergens and diagnosis.

RECENT FINDINGS

Common causes of OACD include rubber components, epoxies and preservatives. New exposure sources for these allergens continue to be described. Often these exposure sources are related to the changing world around us, such as allergens related to smartphones and technology, and personal protective equipment-related exposures during the COVID-19 pandemic. New allergens are also being described, some of which are related to known allergens (e.g. a new epoxy or acrylate component).Accurate diagnosis is critical to effective management of OACD, which may include removing the worker from exposure to the causative allergen. Safety data sheets may not contain complete information and patch testing with specialized series of allergens and workplace materials may be necessary.

SUMMARY

This review provides current evidence about causes of OACD and important aspects of diagnosis. This is important for clinical practice to ensure cases of OACD are not missed.

Quaternary Ammonium Compounds and Contact Dermatitis: A Review and Considerations During the COVID-19 Pandemic

The recent global pandemic has resulted in increased use of quaternary ammonium compounds (QACs). Currently, QACs are active ingredients in 292 disinfectants recommended by the US EPA for use against SARS-CoV-2. Among QACs, benzalkonium chloride (BAK), cetrimonium bromide (CTAB), cetrimonium chloride (CTAC), didecyldimethylammonium chloride (DDAC), cetrimide, quaternium-15, cetylpyridinium chloride (CPC), and benzethonium chloride (BEC) were all identified as potential culprits of skin sensitivity. Given their widespread utilization, additional research is needed to better classify their dermal effects and identify other cross-reactors. In this review, we aimed to expand our knowledge about these QACs to further dissect its potential allergic and irritant dermal effects on healthcare workers during COVID-19.

Allergic contact dermatitis to rubber accelerators in protective gloves: Problems, challenges, and solutions for occupational skin protection

Protective gloves are an elementary component of personal protective equipment in many occupations and are intended to protect the hands from various hazards (e.g., wetness, chemicals, mechanical forces, or thermal stress). This is particularly important when other occupational safety measures (e.g., technical-organizational measures) cannot be implemented or are insufficient. However, it is not uncommon for protective gloves themselves to become a problem, as some of their ingredients (e.g., rubber accelerators) can cause allergic reactions. Accelerators in rubber gloves include thiurams, dithiocarbamates, thiazoles, guanidines, and thioureas. If no alternative means of protection are available, this may even result in abandoning the profession. This article is about rubber accelerators, which are often contained in protective gloves made of different rubber materials (e.g., natural rubber (latex) and nitrile rubber) and may cause delayed-type allergies, as well as related challenges, problems, and solutions for occupational skin protection.