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.

Acrylates in artificial nails-Results of product analyses and glove penetration studies

BACKGROUND

Artificial nail materials are mixtures that are prone to contain several sensitizing (meth)acrylates. It is not known whether the listing of (meth)acrylates is correct in these products' packages. Protective gloves suited for nail work are needed.

OBJECTIVES

To analyse (meth)acrylates in gel nail and acrylic nail products chemically and to compare the results with the information in the product labels, and to study penetration of artificial nail materials through selected disposable gloves.

METHODS

We analysed 31 gel nail products and 6 acrylic nail products for their (meth)acrylate content by gas chromatography-mass spectrometry (GC-MS). We tested the penetration of two nail products through three disposable gloves: nitrile rubber, neoprene rubber and polyvinyl chloride (PVC).

RESULTS

Altogether 32/37 products contained (meth)acrylates. In all of them, there was discrepancy between the listed (meth)acrylates and those discovered in the analysis. The commonest (meth)acrylates were hydroxyethyl methacrylate (HEMA, 20/37 samples) and hydroxypropyl methacrylate (HPMA, 9/37 samples), but many of the product packages failed to declare them. Isobornyl acrylate (IBA) was discovered in nine gel nail products. The neoprene glove could withstand nail gel for 20 min and thin nitrile glove and PVC glove for 5 min. Acrylic nail liquid penetrated through disposable gloves quickly.

CONCLUSIONS

Labelling of artificial nail products was notably incorrect on most products. Requirements for product labelling must be updated so that the risk of sensitization associated with artificial nail products is clearly indicated. Disposable gloves can probably be used short-term in gel nail work, whereas disposable gloves do not protect the user from acrylic nail liquids.

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.

The additive value of patch testing non-commercial test substances and patients' own products in a clinic of occupational dermatology

BACKGROUND

Commercial patch test substances don't cover all occupational contact allergens. Workplace materials and in-house test substances are tested to complement the investigation of occupational skin disease (OSD).

OBJECTIVES

To quantify the additional value of testing workplace materials and non-commercial in-house test substances in the diagnosis of OSD.

MATERIALS AND METHODS

Patients files of 544 patients patch tested at the Finnish Institute of Occupational Health in 2015-2019 were reviewed for occupation, diagnoses, and patch test results.

RESULTS

OSD was diagnosed in 353 (64.9%) of the patients. 206 (37.9%) patients had occupational allergic contact dermatitis (OACD). In 19 (3.5%) patients, the only clues to the diagnoses of OACD were positive reactions to workplace materials, and in 20 (3.7%) patients, the diagnosis of OACD was based on commercially unavailable test substances. In 167 OACD cases diagnosed by commercial test substances, additional causes were found in 17 by testing patients' own and non-commercial test substances. In 43 (7.9%) cases, positive reactions to workplace materials reinforced diagnoses based on commercial test substances. The overall additive value of testing own products was 16.7% (91 cases).

CONCLUSIONS

We would have missed 39 (18.9%) of our 206 OACD cases if we had solely used commercial test substances. This article is protected by copyright. All rights reserved.

Patch test results with the European baseline series, 2019/20-Joint European results of the ESSCA and the EBS working groups of the ESCD, and the GEIDAC

BACKGROUND

Continual analyses of patch test results with the European baseline series (EBS) serve both contact allergy surveillance and auditing the value of included allergens.

OBJECTIVES

To present results of current EBS patch testing, obtained in 53 departments in 13 European countries during 2019 and 2020.

METHODS

Anonymised or pseudonymised individual data and partly aggregated data on demographic/clinical characteristics and patch test rest results with the EBS were prospectively collected and centrally pooled and analysed.

RESULTS

In 2019 and 2020, 22 581 patients were patch tested with the EBS. Sensitization to nickel remained most common (19.8 [19.2-20.4]% positivity [95% confidence interval]). Fragrance mix I and Myroxylon pereirae yielded very similar results with 6.80 (6.43-7.19)% and 6.62 (6.25-7.00)% positivity, respectively. Formaldehyde at 2% aq. yielded almost one percentage point more positive reactions than 1% concentration (2.49 [2.16-2.85]% vs. 1.59 [1.33-1.88]); methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI alone up to around 5% positives. Among the new additions, propolis was most commonly positive (3.48 [3.16-3.82]%), followed by 2-hydroxyethyl methacrylate (2.32 [2.0-2.68]%).

CONCLUSION

Ongoing surveillance on the prevalence of contact sensitization contributes to an up-to-date baseline series containing the most frequent and/or relevant contact sensitizers for routine patch testing in Europe.

Characterization of patients with occupational allergy to two new epoxy hardener compounds

Background

The practical importance of two recently described epoxy hardener allergens—1,3‐benzenedimethanamine, N‐(2‐phenylethyl) derivatives (1,3‐BDMA‐D) and hydrogenated formaldehyde benzenamine polymer (FBAP)—as occupational allergens remains to be defined.

Objectives

To describe patients diagnosed at the Finnish Institute of Occupational Health (FIOH) with positive reactions to 1,3‐BDMA‐D or FBAP.

Methods

We searched FIOH's patch‐test files from January 2017 to December 2020 for patients examined due to suspected occupational contact allergy to epoxy compounds. We analyzed the patch‐test results and sources of exposure to various epoxy hardeners and focused on occupations, symptoms, and the sources of exposure to 1,3‐BDMA‐D and FBAP.

Results

During the study period, 102 patients were examined at FIOH for suspected occupational contact allergy to epoxy compounds. Of these, 19 (19%) were diagnosed with contact allergy to 1,3‐BDMA‐D (n = 10) or FBAP (n = 12). The largest occupational group was sewage pipe reliners (n = 8). Seven different hardener products contained FBAP, whereas 1,3‐BDMA‐D was present in only one hardener used by spray painters.

Conclusions

A substantial number of patients with suspected occupational epoxy resin system allergy tested positive to in‐house test substances of 1,3‐BDMA‐D and/or FBAP.

European patch test results with audit allergens as candidates for inclusion in the European Baseline Series, 2019/20 - Joint results of the ESSCAA and the EBSB working groups of the ESCD, and the GEIDACC

BACKGROUND

In 2019, a number of allergens (haptens), henceforth, 'the audit allergens,' were considered as potential additions to the European baseline series (EBS), namely, sodium metabisulfite, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5 or 5% pet), linalool hydroperoxides (lin-OOH), limonene hydroperoxides (lim-OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments, too.

OBJECTIVES

To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe.

METHODS

Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the ESSCA testing these, as well as further collaborators from the EBS working group of the ESCD, and the Spanish GEIDAC. As patch test outcome, reactions between day (D) 3 and D5 were considered.

RESULTS

Altogether n=12403 patients were tested with any of the audit allergen. Positive reactions were most common to lin-OOH 1% pet. (8.74 (8.14-9.37)), followed by lin-OOH 0.5% pet., and lim-OOH 0.3% pet (5.41 (4.95-5.89)). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72 (4.2-5.28), followed by sodium metabisulfite 1% pet. (3.75 (3.32-4.23)) and Compositae mix 5% pet. (2.31 (1.84-2.87). For some allergens, clinical relevance was frequently difficult to ascertain.

CONCLUSIONS

Despite many positive patch test reactions, it remains controversial whether lin- and lim-OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion among the ESCD members and ultimately decision on their implementation into routine testing. This article is protected by copyright. All rights reserved.

Patterns of positive patch test reactions to formaldehyde and formaldehyde releasers at the Finnish Institute of Occupational Health from 2007 to 2020

BACKGROUND

Formaldehyde is an important contact sensitizer. Formaldehyde releasing substances induce positive reactions in formaldehyde-allergic patients, but there are also reactions independent of formaldehyde allergy. In an earlier study, stronger formaldehyde reactions led to more positive reactions to quaternium-15.

OBJECTIVES

To analyze patterns of positive patch test reactions to formaldehyde and different formaldehyde releasers.

METHODS

Patch test files of 1497 patients investigated during the period November 2007-August 2020 were retrospectively reviewed for positive reactions to formaldehyde and its releasers. During the study period, almost all (≥99.3%) patients were tested with a formaldehyde dilution series and six formaldehyde releasers.

RESULTS

Ninety-three patients tested positive to formaldehyde; 80% of these had positive reactions to at least one formaldehyde releaser, most often benzylhemiformal. There were only nine independent contact allergies to formaldehyde releasers. There were only two reactions to 2-bromo-2-nitropropane-1,3-diol and they occurred in formaldehyde-negative patients. In patients with extreme (+++) reactions to formaldehyde, concomitant positive reactions to any of the other 11 investigated formaldehyde releasers were more common than in patients with milder formaldehyde reactions.

CONCLUSIONS

Strong formaldehyde reactions were associated with positive reactions to formaldehyde releasers.

European Surveillance System on Contact Allergies (ESSCA): Characteristics of patients patch tested and diagnosed with irritant contact dermatitis

BACKGROUND

Irritant contact dermatitis (ICD) is caused by the acute locally toxic effect of a strong irritant, or the cumulative exposure to various weaker physical and/or chemical irritants.

OBJECTIVES

To describe the characteristics of patients with ICD in the population patch tested in the European Surveillance System on Contact Allergies (ESSCA; www.essca-dc.org) database.

METHODS

Data collected by the ESSCA in consecutively patch-tested patients from January 2009 to December 2018 were analyzed.

RESULTS

Of the 68 072 patients, 8702 were diagnosed with ICD (without concomitant allergic contact dermatitis [ACD]). Hand and face were the most reported anatomical sites, and 45.7% of the ICD was occupational ICD (OICD). The highest proportions of OICD were found in metal turners, bakers, pastry cooks, and confectionery makers. Among patients diagnosed with ICD, 45% were found sensitized with no relevance for the current disease.

CONCLUSIONS

The hands were mainly involved in OICD also in the subgroup of patients with contact dermatitis, in whom relevant contact sensitization had been ruled out, emphasizing the need for limiting irritant exposures. However, in difficult-to-treat contact dermatitis, unrecognized contact allergy, or unrecognized clinical relevance of identified allergies owing to incomplete or wrong product ingredient information must always be considered.

Allergic contact dermatitis and other occupational skin diseases in health care workers in the Finnish Register of Occupational Diseases in 2005-2016

BACKGROUND

Health care workers are an important risk group for occupational skin disease (OSD).

AIMS

To study diagnoses and causes of OSDs in health care workers in the Finnish Register of Occupational Diseases (FROD) in 2005-2016.

METHODS

We searched the FROD for dermatological cases (a) in health care-related occupations defined by ISCO-08 and (b) in the industrial branch of health care defined by European industry standard classification system (NACE rev. 2).

RESULTS

Health care workers comprised 19% of all OSD cases in the FROD, and irritant contact dermatitis dominated the diagnoses. Nurses and assistant nurses were the largest occupational groups with incidence rates of 3.3 and 2.7/10 000 person years, respectively. Rubber chemicals were by far the most common causative agents of allergic contact dermatitis (ACD) followed by preservatives, the latter mainly comprising isothiazolinones and formaldehyde. Acrylates were important allergens in dental professions. Metals and coconut fatty acid derivatives were the next largest causative groups for ACD. Drugs caused only 1% of the ACD cases.

CONCLUSIONS

Workers in different health care occupations do not have a uniform risk for OSD, but they share the risk for ACD due to rubber chemicals and various preservatives.

Hairdressers' occupational skin diseases in the Finnish Register of Occupational Diseases in a period of 14 years

BACKGROUND

Hairdressers have a high risk of occupational contact dermatitis caused by exposure to wet work and allergens in hairdressing chemicals.

OBJECTIVES

To examine the distribution of diagnoses of occupational skin diseases (OSDs) and their main causes in hairdressers based on a national register data on occupational diseases.

METHODS

We retrieved cases of recognized OSDs in hairdressers from the Finnish Register of Occupational Diseases (FROD) in years 2005-2018.

RESULTS

During the 14-year period, a total of 290 cases of recognized OSD in hairdressers were registered in the FROD. Allergic contact dermatitis (ACD) was diagnosed in 54%, irritant contact dermatitis in 44%, and contact urticaria (CU) in 5% of them. ACD was most commonly caused by hair dye products and their ingredients (N = 57), persulfates (N = 35), and preservatives (N = 35; mainly isothiazolinones). Acrylates emerged as hairdressers' occupational contact allergens (N = 8) probably due to introduction of structure nails into hair salons. Persulfates was the most common cause of CU.

CONCLUSIONS

ACD was the most common OSD in hairdressers. Our analysis confirms that preservatives are important causes of ACD in hairdressers in addition to hair dye products and persulfates. Acrylates emerged as hairdressers' occupational contact allergens, but contact allergy to perming agents remained rare.

Occupational buckwheat allergy as a cause of allergic rhinitis, asthma, contact urticaria and anaphylaxis-An emerging problem in food-handling occupations?

Buckwheat is a known, though uncommon, allergen in occupational settings. It has recently gained popularity as healthy food and as an ingredient in gluten-free diets. We describe a series of six patient cases with occupational immediate allergy to buckwheat. Three cooks, two bakers, and a worker in a grocery store were occupationally exposed to buckwheat flour and developed immediate allergy to buckwheat, which was confirmed by skin prick testing and measurement of specific immunoglobulin E antibodies. Four of the patients were diagnosed with occupational asthma, four with occupational rhinitis, and two with occupational contact urticaria caused by buckwheat. Three of the six patients suffered anaphylaxis as consequence of their occupational buckwheat allergy after ingestion of food that contained buckwheat. The high rate of life-threatening reactions, together with a short exposure time to buckwheat before sensitization occurred in these cases, highlights the importance of a detailed occupational history and a high index of suspicion for occupational food allergens.

Formaldehyde 2% is not a useful means of detecting allergy to formaldehyde releasers- results of the ESSCA network, 2015-2018

BACKGROUND

Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq.

OBJECTIVES

To determine the frequency of sensitization to formaldehyde 2% aq. and co-reactivity with FRs. To establish whether there is justification for including FRs in the EBS.

MATERIALS AND METHODS

A 4-year, multi-center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs.

RESULTS

A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co-reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium-15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3-dimethylol-5, 5-dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2-bromo-2-nitropropane-1,3-diol 0.5% pet. This demonstrates that co-reactivity varies between FRs and formaldehyde, from being virtually non-existent in 2-bromo-2-nitropropane-1,3-diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] -0.02 to 0.02)], to only weak concordance for quaternium-15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance.

CONCLUSIONS

Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen.

Contact urticaria and protein contact dermatitis in the Finnish Register of Occupational Diseases in a period of 12 years

BACKGROUND

Although occupational contact urticaria (CU) and protein contact dermatitis (PCD) are considered frequent among workers with exposure to proteinaceous materials, data on occupations at risk and the main causes of these occupational skin diseases are relatively limited.

OBJECTIVES

To report the causative agents and risk occupations for CU and PCD in the Finnish Register of Occupational Diseases (FROD).

METHODS

We retrieved from the FROD all recognized cases of CU/PCD in the years 2005-2016.

RESULTS

With 570 cases, CU and PCD constituted 11% of all recognized cases of occupational skin diseases in the study period. Occupations with the highest incidence of CU/PCD included bakers, chefs and cooks, farmers and farm workers, veterinarians, gardeners, and hairdressers. The most common causative agents were cow dander and flour and grain, followed by natural rubber latex (NRL) and other food. In food-related occupations, wheat and other flours were by far the most common cause of CU/PCD, with 76 cases, whereas fish and other animal-derived food caused 33 and other plant-derived food caused 23 cases.

CONCLUSIONS

Apart from the Finnish peculiarity of cow dander allergy, a striking finding was a large share of CU/PCD caused by flours in food handlers as compared to other food.

Occupational rhinitis, asthma, and contact urticaria from IgE-mediated allergy to pork

We describe four cases of slaughterhouse workers with occupational immediate allergy to raw pork allergens, confirmed by positive skin prick testing and specific immunoglobulin E (IgE) antibodies. Our first patient was diagnosed with occupational asthma from raw pork allergens. Two patients were diagnosed with occupational rhinitis caused by raw pork allergens, which was confirmed by a nasal provocation test. One of these also had occupational contact urticaria caused by raw pork meat. We were unable to diagnose an occupational respiratory or skin disease in the fourth patient, despite signs of immediate sensitization to raw pork meat from occupational exposure. Based on proper diagnoses, measures to prevent allergen exposure were taken, which led to the improvement of symptoms in these four patients. The present patient cases highlight the importance of recognition of early signs of occupational allergy and identification of causative allergens in order to allow avoidance of allergens, with the aim of preventing persistence and worsening of symptoms.

Allergic reactions to lower concentrations of nickel sulfate and formaldehyde often appear later than reactions to higher concentrations

BACKGROUND

A late-appearing patch test reaction may be a sign of active sensitization or represent a delayed elicitation reaction.

OBJECTIVES

To retrospectively study the effect of concentration on the time course of allergic reactions to routine concentration dilution series of formaldehyde and nickel sulfate.

METHODS

We tested concentration dilution series of 2%, 1%, 0.32% and 0.1% formaldehyde and 5%, 1.6%, 0.5% and 0.16% nickel sulfate, respectively. The last readings were performed on day 4 to day 6. We included patients with allergic reactions to either of the two lowest concentrations in each dilution series and whose tests had been read three times.

RESULTS

Forty-two nickel-allergic and 23 formaldehyde-allergic patients fulfilled the inclusion criteria. In 26 (62%) of the nickel-sensitive patients, reactions to lower concentrations appeared later than reactions to the highest concentration. Of the formaldehyde-sensitive patients, 17 (74%) developed one or two allergic reactions to lower concentrations later than reactions to the highest concentration, and one (4%) patient developed allergic reactions to lower concentrations sooner than a reaction to the highest concentration. The remaining patients showed all allergic reactions at the same reading.

CONCLUSIONS

In these selected, relatively strongly sensitized patients, allergic reactions to lower concentrations quite regularly appeared later than reactions to higher concentrations.

Skin exposure to epoxy chemicals in construction coating, assessed by observation, interviews, and measurements

BACKGROUND

Epoxy resin systems (ERSs) are among the leading causes of occupational allergic contact dermatitis.

OBJECTIVES

To identify riskful exposures and sources of skin exposure, and to quantify skin exposure to diglycidyl ether of bisphenol A (DGEBA) epoxy monomer, in construction coating work.

METHODS

Skin exposure to epoxy chemicals was studied in 5 coating companies through (a) interviews and visual observation, (b) quantifying DGEBA on 12 workers' skin by tape-stripping, (c) measuring DGEBA on 23 surfaces by wipe-sampling, and (d) quantifying DGEBA in new sewage pipe. Acetone extracts of the tapes, wipes and sawdust from a newly hardened sewage pipe were analysed by gas chromatography/mass spectrometry.

RESULTS

Identified riskful exposures were, for example, mixing ERSs, handling coating pots, and working above shoulder level. Epoxy stains on, for example, tools, equipment and clothing were seen in all workplaces. Protective gloves were of varying quality, and were not always suitable for chemicals. The amount of DGEBA on the workers' skin varied considerably. All screened tool handles were contaminated. Two-day-old epoxy sewage pipe contained 3.2% DGEBA.

CONCLUSIONS

Construction coating entails skin contact with ERSs directly and via contaminated surfaces, personal protective equipment, and recently hardened epoxy materials. Observation is a useful method for assessing skin exposure in coating work.

Occupational contact dermatitis caused by 1,3-benzenedimethanamine, N-(2-phenylethyl) derivatives in hardeners for epoxy paints and coatings

BACKGROUND

Amines in epoxy hardeners are significant causes of occupational allergic contact dermatitis among workers who use epoxy resin systems.

OBJECTIVES

To describe a novel group of contact allergens: N-(2-phenylethyl) derivatives of the reactive amine 1,3-benzenedimethanamine (1,3-BDMA).

METHODS

We describe the clinical examinations and exposure of 6 patients with occupational contact allergy to derivatives of 1,3-BDMA.

RESULTS

Of the 6 patients, 4 were spray painters who used epoxy paints, 1 was a floor layer who handled a variety of epoxy coatings, and 1 was a worker in epoxy hardener manufacture. We were able to confirm exposure to epoxy hardeners that contained derivatives of 1,3-BDMA in 5 of the 6 sensitized patients. Despite the close structural resemblance between derivatives of 1,3-BDMA and m-xylylenediamine (MXDA), only 3 patients reacted positively to MXDA. Concomitant contact allergy to diglycidyl ether of bisphenol A resin was seen in 2 of the 6 patients.

CONCLUSIONS

Because of the lack of a commercially available patch test substance, the diagnosis of contact allergy to derivatives of 1,3-BDMA requires patch testing with either the epoxy hardener product or a hardener ingredient that contains the derivatives of 1,3-BDMA.

Allergen skin prick testing in early childhood: reproducibility and prediction of allergic symptoms into early adulthood

OBJECTIVE

To assess the predictive value of skin prick testing in early childhood on subsequent allergic symptoms up to adult age.

STUDY DESIGN

A cohort of 200 unselected healthy newborns was prospectively followed from birth to 20 years of age. Of them, 163 (82%) were reassessed at age 5 years, 150 (76%) at age 11 years, and 164 (83%) at age 20 years with a skin prick test that included 11 common allergens. On the basis of clinical examination and structured interview, the occurrence of atopic dermatitis, allergic rhinoconjunctivitis, recurrent wheezing, and symptoms of food hypersensitivity were recorded at each of the follow-up visits.

RESULTS

The reproducibility of skin prick test positivity at age 5 years was 100% at ages 11 and 20 years, ie, none of the skin prick-positive subjects turned negative during the follow-up. Gaining of new sensitizations to aeroallergens was common. Skin prick test positivity at age 5 years predicted allergic symptoms at ages 11 (sensitivity 28%, specificity 94%) and 20 years (sensitivity 23%, specificity 91%) but not atopic dermatitis.

CONCLUSIONS

Skin prick test positivity at age 5 years strongly predicts later skin prick test positivity and is associated with respiratory symptoms, ie, allergic rhinoconjunctivitis and recurrent wheezing, at ages 11 and 20 years. However, skin prick test negativity at age 5 years does not exclude sensitization and allergic symptoms at a later age.

Sub-ppm electrical detection of hydrogen sulfide gas at room temperature based on printed copper acetate–gold nanoparticle composite films

This paper presents the sub-ppm level electrical detection of H₂S gas at room temperature using printed copper acetate–gold nanoparticle composite films either on (A) silver or (B) gold/AuNP electrodes.

Occupational contact dermatitis caused by D-limonene

BACKGROUND

Limonene is widely used as a fragrance substance and solvent in cleansing products. Oxidized limonene is a frequent contact allergen among consumers of cosmetics, personal care products, and scented household cleaning products. Less is known about the sources of occupational exposure and occupational contact dermatitis caused by limonene.

OBJECTIVE

To report 14 patients with occupational contact allergy to limonene.

METHODS

The patients were examined in 2008-2013. An in-house preparation of oxidized limonene was patch tested as 3% and 5% in petrolatum from 2008 to August 2010, and after this as 3%, 1% and 0.3% pet. From 2012 onwards, a commercial test substance of limonene hydroperoxides was also used. We assessed the patients' occupational and domestic exposure to limonene.

RESULTS

Occupational limonene allergy was observed in workers who used limonene-containing machine-cleaning detergents and hand cleansers, and in workers who used limonene-containing surface cleaners and dishwashing liquids similar to those used by consumers. In 3 cases, the occupational limonene allergy resulted from work-related use of limonene-containing, leave-on cosmetic products.

CONCLUSIONS

Limonene is a frequent occupational sensitizer in hand cleansers and cleaning products. Occupational limonene contact allergy may also be caused by exposure to cosmetic products scented with limonene.