Occupational contact urticaria caused by cyclic acid anhydrides

Contact urticaria: Frequency, elicitors and cofactors in three cohorts (Information Network of Departments of Dermatology; Network of Anaphylaxis; and Department of Dermatology, University Hospital Erlangen, Germany)

BACKGROUND

Contact urticaria (CU) is an infrequent, mostly occupational disease that may be life-threatening (CU syndrome stage 4).

OBJECTIVES

To identify the current frequency, elicitors and cofactors of CU.

PATIENTS

Three cohorts were retrospectively analysed for CU: (a) patients from the Information Network of Departments of Dermatology (IVDK) database (2000-2014; n = 159 947); (b) patients from an allergy unit (Department of Dermatology, University Hospital Erlangen, 2000-2015; n = 4741); and (c) patients from the Anaphylaxis Registry (2007-2015: 6365 reported cases, including 2473 patients with Ring and Messmer grade III-IV reactions) for severe cases with skin/mucosal manifestations occurring at the workplace vs cases not occurring at the workplace (n = 68 vs n = 1821).

RESULTS

Four hundred and forty-eight CU patients (0.28%) were diagnosed in the IVDK cohort, and 16 (0.34%) (10 of immunological aetiology, and 6 of non-immunological aetiology) in the Erlangen cohort. The most frequent elicitors in the IVDK cohort were cosmetics, creams, sun protection agents (although these were less frequent in CU patients than in controls without CU; 26.8% vs 35.6%, P < .0001), and gloves (significantly more frequent in CU patients than in controls; 18.1% vs 6.5%, P < .0001). The most frequent elicitors in the Erlangen cohort were natural rubber latex and sorbic acid. Among the MOAHLFA index characteristics, in both cohorts occupational disease was more common in CU patients than in patients without CU. CU was significantly associated with allergic rhinitis and allergic asthma. Wet work was a relevant cofactor. In the Anaphylaxis Registry, 19 cases (0.3%) were identified with severe reactions including skin symptoms at the workplace linked to common occupational elicitors.

CONCLUSIONS

CU is a rare occupational skin manifestation with a frequency of <0.4% in the examined patients; it may, however, progress to anaphylaxis. Preventive measures are important, and should take into account the identified elicitors and cofactors.

Occupational Asthma From Epoxy Compounds

BACKGROUND

Two-component epoxy resin systems (ERSs) composed of epoxy resin and polyamine hardeners are extensively used in industrial and construction coating. Triglycidyl isocyanurate (TGIC) is another type of epoxy derivative, mostly encountered in polyester powder paints. Epoxy compounds are well-known skin sensitizers, but their respiratory-sensitizing potential is largely unknown.

OBJECTIVE

To report patients examined for occupational asthma (OA) from epoxy compounds.

METHODS

We retrospectively reviewed patient files of cases tested with a placebo-controlled specific inhalation challenge (SIC) according to their workplace exposure-either by mixing epoxy resin and the polyamine hardener of a 2-component paint or by dusting or heating TGIC-containing powder paint. The data were collected from the Finnish Institute of Occupational Health, Helsinki, Finland, and at Fundación Jiménez Díaz Hospital, Madrid, Spain, during 1997 to 2018. We also measured airborne polyamine and solvent vapors at the workplace and during SIC with ERSs.

RESULTS

Altogether 113 patients with work-related asthma symptoms underwent SIC with ERSs. Fifteen cases (13%) had positive SIC reactions confirming OA; in 12 cases reactions were late-type, in 1 case early, and in 2 cases combined. The median duration of exposure for patients with OA was 10 years; 2 of them (13%) had a diagnosis of allergic contact dermatitis from ERS compounds. In addition, 3 cases had a positive SIC reaction to TGIC. The airborne polyamine levels measured were low.

CONCLUSION

ERSs and TGIC can cause sensitizer-induced OA in some exposed workers. Respiratory exposure to ERSs is difficult to demonstrate using air measurements.

Immediate Hypersensitivity Reactions Induced by Triamcinolone in a Patient with Atopic Dermatitis

Corticosteroids are potent anti-inflammatory and anti-allergic agents used in the treatment of various inflammatory diseases, including allergic disease. They are frequently considered the therapy-of-choice for many skin diseases. However, allergic reactions caused by corticosteroids have been reported. Among these, delayed reactions to topical steroids are more common, whereas immediate reactions to systemic steroids are rare. Herein, we report the case of a 32-year-old woman with triamcinolone-induced immediate hypersensitivity reaction, in which the patient had a positive prick test result with triamcinolone. She has had atopic dermatitis (AD) for three years. She had used systemic steroid, cyclosporine, and antihistamine with topical steroids for AD. In clinic, approximately 10 minutes after intralesional injection of triamcinolone, she complained of erythematous patches with slight elevation and itching on the face, trunk, and both hands. After intravenous injection of dexamethasone, her symptoms got worse. After treatment with epinephrine, all symptoms resolved within two hours. We performed an open test and skin prick test. She had a positive result only from the prick test with triamcinolone; all other steroids showed negative results from the open tests. Dermatologists should be aware of the possibility of anaphylaxis or other allergic hypersensitivity in response to corticosteroids.

3-(Bromomethyl)-2-chloro-4-(methylsulfonyl)- benzoic acid: a new cause of sensitiser induced occupational asthma, rhinitis and urticaria

OBJECTIVES

3-(Bromomethyl)-2-chloro-4-(methylsulfonyl)-benzoic acid (BCMBA) has not previously been identified as a respiratory sensitiser. We detected two cases who presented respiratory and urticaria symptoms related to BCMBA and had positive skin prick tests to the agent. Subsequently, we conducted outbreak investigations at the BCMBA-producing factory and performed clinical examinations to confirm occupational diseases.

METHODS

The outbreak investigations included observations of work processes, assessment of exposure, a medical survey with a questionnaire and skin prick tests with 0.5% BCMBA water solution on 85 exposed workers and 9 unexposed workers. We used specific inhalation or nasal challenge and open skin application test to investigate BCMBA-related occupational asthma, rhinitis and contact urticaria.

RESULTS

We identified nine workers with respiratory and/or skin symptoms and positive skin prick tests to BCMBA in a chemical factory. A survey among chemical factory workers indicated a BCMBA-related sensitisation rate of 8% among all exposed workers; the rate was highest (25%) among production workers in the production hall. Sensitisation was detected only in workers with the estimated highest exposure levels. Six cases of occupational asthma, rhinitis and/or contact urticaria caused by BCMBA were confirmed with challenge tests. Asthma-provoking doses in specific inhalation challenges were very low (0.03% or 0.3% BCMBA in lactose).

CONCLUSIONS

We identified a new low molecular weight agent causing occupational asthma, rhinitis and contact urticaria. A typical clinical picture of allergic diseases and positive skin prick tests suggest underlying IgE-mediated disease mechanisms. Stringent exposure control measures are needed in order to prevent BCMBA-related diseases.

Checklist for a complete chronic urticaria medical history: an easy tool

BACKGROUND

Existing guidelines do not offer a quick, efficient alternative to the patient's recollection of relevant clinical features during anamnesis and physical examination for chronic urticaria (CU). This study aimed to identify specific items reflecting the main characteristics of CU that should be included in a comprehensive medical history for patients with CU. We also aimed to clarify possible eliciting factors for CU to support accurate diagnosis of the disease.

METHODS

A panel of postgraduate dermatologists conducted a literature search for relevant studies on CU using Medline, the Cochrane database, and PubMed.

RESULTS

We identified82 articles from which we drew a collection of items to inform development of an easy-to-use checklist and collection of items that should be included in a correct medical history. The final version of the checklist included42 items across two areas: essential clues for anamnesis and diagnosis of CU; and typical symptoms/parameters or characteristics according to subtype, etiology, and laboratory findings. Items included time of disease onset; duration, shape, size, color, and distribution of wheals; associated angioedema; atopy; and triggering factors.

CONCLUSIONS

Our guide provides an easy-to-use tool to support clinicians to focus, orient themselves, and save time in medical consultations for CU, allowing better diagnosis and management of this disease.

Occupational contact urticaria and protein contact dermatitis: causes and concomitant airway diseases

BACKGROUND

Contact urticaria (CU) and protein contact dermatitis (PCD) are mainly induced by an immediate, IgE-mediated immunological mechanism. Immediate sensitization is also linked to asthma and/or allergic rhinitis.

OBJECTIVES

To report causes of work-induced CU and PCD, and to evaluate the occurrence of concomitant airway diseases.

METHODS

We retrospectively reviewed the patient files of cases diagnosed with CU or PCD at the Finnish Institute of Occupational Health during 1995-2011. We obtained data on occupation, exposures, clinical and immunological test results, and diagnosed occupational skin and respiratory diseases.

RESULTS

Altogether, 291 cases of occupational CU or PCD were diagnosed during the study period. The most common causes were flour, cow dander, natural rubber latex and acid anhydrides. Concomitant occupational asthma caused by the same agent as the skin disease was detected in 60 patients (21%), and occupational rhinitis was detected in 111 patients (38%).

CONCLUSIONS

Almost half of the patients (46%) with occupational CU and PCD had concomitant occupational airway disease. Patients with CU/PCD should always be asked about respiratory symptoms, and preventive measures at the workplace should include protection of both the skin and the airways.

Phthalic anhydride: Illustrating a conundrum in chemical allergy

Although a substantial number of chemicals has the ability to bind covalently to proteins and thereby, given sufficient exposure, induce a state of sensitization, only a small minority appear to be able to cause allergic hypersensitivity of the respiratory tract; the great majority being exclusively skin sensitizers. The key mechanistic drivers for the differentiation between skin and respiratory sensitization are already well characterized at the cellular/cytokine level. However, at both the chemical level and in terms of predictive toxicology, matters are much less clear. In the present article, phthalic anhydride is used as an exemplar, since it displays a particularly differentiated profile as a chemical allergen. Whereas most respiratory sensitizers are known also to give rise to delayed skin reactions, evidence for phthalic anhydride suggests that it only causes immediate type allergy. Chemically, phthalic anhydride can be presumed to react similar to other respiratory sensitizing anhydrides; in predictive tests for skin sensitization, phthalic anhydride is clearly positive, a property it has in common with all other chemical respiratory allergens. Thus, in the context of interpreting predictive toxicology tests for skin sensitization, the inference is that negative results demonstrate an absence of both skin- and respiratory-sensitizing capacity.

Mechanistic understanding of molecular initiating events (MIEs) using NMR spectroscopy

Toxicological risk assessments in the 21^st century are increasingly being driven by the Adverse Outcome Pathways (AOP) conceptual framework in which the Molecular Initiating Event (MIE) is of fundamental importance to pathway progression. For those MIEs that involve covalent chemical reactions, such as protein haptenation, determination of relative rates and mechanisms of reactions is a prerequisite for their understanding. The utility of NMR spectroscopy as an experimental technique for effectively providing reaction rate and mechanistic information for early assessment of likely MIE(s) has been demonstrated. To demonstrate the concept, model systems exemplifying common chemical reactions involved in the covalent modification of proteins were utilized; these involved chemical reactions of electrophilic species (representing different mechanistic classes) with simple amine and thiol nucleophiles acting as surrogates for the reactive groups of lysine and cysteine protein side chains respectively. Such molecular interactions are recognized as critical mechanisms in a variety of chemical and drug toxicities, including respiratory and skin sensitization and liver toxicity as well as being the key mechanism of action for a number of therapeutic agents.

Prick testing with chemicals in the diagnosis of occupational contact urticaria and respiratory diseases

BACKGROUND

Little is known about the use of prick tests with chemicals in diagnosing occupational diseases.

OBJECTIVE

To evaluate the use of prick tests in the diagnosis of occupational contact urticaria, asthma and rhinitis caused by chemicals (undertaken at the Finnish Institute of Occupational Health).

MATERIAL AND METHODS

We retrospectively reviewed the patient and test files for the period 1 January 1991 to 31 May 2011. Prick tests were performed with chemical solutions and human serum albumin (HSA)-chemical conjugates.

RESULTS

Positive prick test reactions to isocyanate-HSA conjugates were associated with isocyanate-specific IgE in all 20 patients, and 17 patients had a relevant occupational disease. Positive reactions to chloramine-T-HSA conjugates in 10 patients also indicated the presence of specific IgE, although occupational diseases were not always diagnosed. Eleven of 17 patients with positive reactions to persulfate solutions were diagnosed with an occupational disease. Methacrylates, colophonium-related substances, amine hardeners, ethanolamines, glutaraldehyde, glyoxal, pyrocatechol and ammonium thioglycolate did not elicit any relevant prick test reactions. No generalized reactions were detected.

CONCLUSION

Prick tests can be safely used for diagnosing contact urticaria, asthma and rhinitis caused by isocyanates, chloramine-T, persulfates, and chlorhexidine, but the results should be carefully interpreted and related to clinical symptoms and other diagnostic tests.

Contact allergy to epoxy hardeners

BACKGROUND

Diglycidylether of bisphenol A resin is the most important sensitizer in epoxy systems, but a minority of patients develop concomitant or solitary contact allergy to epoxy hardeners. At the Finnish Institute of Occupational Health, several in-house test substances of epoxy hardeners have been tested in a special epoxy compound patch test series.

OBJECTIVES

To analyse the frequency and clinical relevance of allergic reactions to different epoxy hardeners.

METHODS

Test files (January 1991 to March 2013) were screened for contact allergy to different epoxy hardeners, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure.

RESULTS

The most commonly positive epoxy hardeners were m-xylylenediamine (n = 24), 2,4,6-tris-(dimethylaminomethyl)phenol (tris-DMP; n = 14), isophorone-diamine (n = 12), and diethylenetriamine (n = 9). Trimethylhexamethylenediamine (n = 7), tetraethylenepentamine (n = 4), and triethylenetetramine (n = 2) elicited some reactions, although most patients were found to have no specific exposure. Allergic reactions to hexamethylenetetramine, dimethylaminopropylamine and ethylenediamine dihydrochloride were not related to epoxy products.

CONCLUSIONS

Tris-DMP is an important sensitizer in epoxy hardeners, and should be included in the patch test series of epoxy chemicals.

Immunoglobulin E-binding autoantigens: biochemical characterization and clinical relevance

Although immediate-Type I skin reactions to human dander have been described six decades ago, only the recent application of molecular biology to allergology research allowed fast and detailed characterization of IgE-binding autoantigens. These can be functionally subdivided into three classes: (1) self-antigens with sequence homology to environmental allergens belonging to the class of phylogenetically conserved proteins, (2) self-antigens without sequence homology to known environmental allergens, and (3) chemically modified self-antigens deriving from workplace exposure. As environmental allergens, also IgE-binding autoantigens belong to different protein families without common structural features that would explain their IgE-binding capability. Many of the self-antigens showing sequence homology to environmental allergens, are phylogenetically conserved proteins like manganese dependent superoxide dismutase, thioredoxin or cyclopilin. Their IgE-binding capability can be explained by molecular mimicry resulting from shared B-cell epitopes. A common factor of IgE-binding self-antigens without sequence homology to known environmental allergens is that they elicit IgE responses only in individuals suffering from long-lasting atopic diseases. In contrast, IgE-mediated reactions to modified self-antigens might be explained with the generation of novel B-cell epitopes. Chemically modified self-antigens are likely to be recognized as non-self by the immune system. The clinical relevance of IgE responses to self-antigens remains largely unclear. Well documented is their ability to induce immediate Type I skin reactions in vivo, and to induce mediator release from effector cells of sensitized individuals in vitro. Based on these observations it is reasonable to assume that IgE-mediated cross-linking of FcRIε receptors on effector cells can elicit the same symptoms as those induced by environmental allergens, and this could explain exacerbations of chronic allergic diseases in the absence of external exposure. However, because most of the described IgE-binding self-antigens are intracellular proteins normally not accessible for antigen-antibody interactions, local release of the antigens is required to explain the induction of symptoms.

Evidence-based guidelines for the prevention, identification and management of occupational contact dermatitis and urticaria

BACKGROUND

Occupational contact dermatitis is the most frequently reported work-related skin disease in many countries. A systematic review was commissioned by the British Occupational Health Research Foundation in response to a House of Lords Science and Technology Committee recommendation.

OBJECTIVES

The systematic review aims to improve the prevention, identification and management of occupational contact dermatitis and urticaria by providing evidence-based recommendations.

METHODS

The literature was searched systematically using Medline and Embase for English-language articles published up to the end of September 2009. Evidence-based statements and recommendations were graded using the Royal College of General Practitioner's three-star system and the revised Scottish Intercollegiate Guidelines Network grading system.

RESULTS

Three thousand one hundred and fifty-five abstracts were identified and screened. From these, 786 full papers were obtained and appraised. One hundred and nineteen of these studies were used to produce 36 graded evidence statements and 10 key recommendations.

CONCLUSIONS

This evidence review and its recommendations focus on interventions and outcomes to provide a robust approach to the prevention, identification and occupational management of occupational contact dermatitis and urticaria, based on and using the best available medical evidence.

Chemical allergens--what are the issues?

Chemical allergy describes the adverse health effects that may result when exposure to a chemical elicits an immune response. Allergy develops in two phases. In the first phase, exposure of an inherently susceptible subject results in stimulation of an immune response or immunological priming. If the then sensitised subject is exposed on a subsequent occasion to the same chemical then an accelerated and more aggressive secondary immune response will be provoked resulting in inflammation and the signs and symptoms of a clinically discernible allergic reaction. The two forms of chemical allergy of greatest relevance for occupational toxicology are skin sensitisation resulting in allergic contact dermatitis, and sensitisation of the respiratory tract associated with occupational rhinitis and asthma. In this brief survey we identify what we believe currently represent the key issues and key challenges in these areas.

Contact urticaria: present scenario

Immunological contact urticaria is a hypersensitivity reaction that appears on the skin following contact with an eliciting substance. Recent advances in our understanding of the molecular mechanism and pathogenesis of this reaction have altered its classification, diagnosis, and treatment. We discuss classification, epidemiology, diagnosis, testing, and treatment options that are available to patients with contact urticaria.