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.

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.

Occupational contact allergy to methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone.

BACKGROUND: Methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) and MI are common preservatives in industrial and household products and in cosmetics. Occupational contact allergy to MCI/MI or MI has been reported among painters and paint factory workers in particular. OBJECTIVES: To retrospectively describe patients with occupational contact allergy to MCI/MI and MI at the Finnish Institute of Occupational Health (FIOH). METHODS: Patch test files and clinical records of patients examined at the FIOH between January 2002 and February 2013 were reviewed to identify the patients. RESULTS: Seventy-two of 1745 patients showed positive reactions to MCI/MI and/or MI. Of these, 36 were occupational cases, and 31 were diagnosed during the second half of the study period. Hairdressers and beauticians, mechanics and repairmen, and machinists were the most significant occupational groups, followed by painters and paint factory workers, and café and restaurant workers. CONCLUSIONS: We observed a sixfold increase in the number of occupational cases in the second half of the study period as compared with the first half. Liquid soaps and industrial hand cleansers were common sources of exposure to MCI/MI or MI. A total of 33% of the patients used products without any mention of MCI/MI or MI in safety data sheets or product declarations.

Occupational contact dermatitis caused by aniline epoxy resins in the aircraft industry.

BACKGROUND: Tetraglycidyl-4,4'-methylenedianiline (TGMDA) is an aniline epoxy resin used in, for example, resin systems of pre-impregnated composite materials (prepregs) of the aircraft industry. Allergic contact dermatitis caused by TGMDA in prepregs has been described previously. OBJECTIVES: To report on 9 patients with occupational allergic contact dermatitis caused by TGMDA in epoxy glues used in helicopter assembly. METHODS: The patients were examined with patch testing at the Finnish Institute of Occupational Health in 2004-2009. The first patient was diagnosed by testing both components of two epoxy glues from the workplace, and was also tested with glue ingredients, including TGMDA. The following patients were tested with the glues and TGMDA. The resin parts of the glues were analysed for their epoxy compounds, including TGMDA. RESULTS: All of the patients had a patch test reaction to one or both of the resin parts of the TGMDA-containing glues. Eight of them had a strong allergic reaction to TGMDA, and one had a doubtful reaction to TGMDA. Two of the patients also had an allergic reaction to triglycidyl-p-aminophenol (TGPAP), another aniline epoxy resin, which was not present in the TGMDA-containing glues. CONCLUSIONS: In aircraft industry workers with suspected occupational dermatitis, aniline epoxy resins should be considered and patch tested as possible contact allergens.

Contact allergy to reactive diluents and related aliphatic epoxy resins.

BACKGROUND: Diglycidyl ether of bisphenol A resin (DGEBA-R) is the most common sensitizer in epoxy systems, but a minority of patients also develop contact allergy to reactive diluents. OBJECTIVES: To analyse the frequency and clinical relevance of allergic reactions to different epoxy reactive diluents and related aliphatic epoxy resins. METHODS: Test files (January 1991 to June 2014) were screened, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. RESULTS: A total of 67 patients reacted to at least one of the compounds. The largest numbers of allergic reactions were to phenyl glycidyl ether (PGE; n = 41), 1,4-butanediol diglycidyl ether (BDDGE; n = 34), and p-tert-butylphenyl glycidyl ether (PTBPGE; n = 19). Ten of the patients did not have contact allergy to DGEBA-R. The reactions of 5 of these were related to the use of BDDGE-containing products. We found no significant exposure to PGE or PTBPGE in patients sensitized to them, but some of the patients had used cresyl glycidyl ether-containing products. CONCLUSIONS: Allergic reactions to reactive diluents and related aliphatic epoxy resins usually occurred together with reactions to DGEBA-R. BDDGE was the clinically most significant compound, and was the sole cause of occupational allergic contact dermatitis in 3 patients.

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.

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.

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.

Screening occupational contact allergy to bisphenol F epoxy resin.

BACKGROUND: Epoxy resins based on diglycidyl ether of bisphenol F (DGEBF) are widely used as such in applications requiring chemical resistance, and also together with diglycidyl ether of bisphenol A resin (DGEBA-R). Concomitant patch test reactions to DGEBA-R and DGEBF resin (DGEBF-R) are common. Previous studies have yielded conflicting results on the frequency of independent DGEBF-R contact allergies. OBJECTIVES: To report the results of over 11 years of screening with DGEBF-R. METHODS: An in-house test substance of DGEBF-R (Epikote 862) was tested in the baseline patch test series, first at 1% and later at 0.25%. Test files were screened for allergic reactions to DGEBF-R and DGEBA-R, and the clinical records of positively reacting patients were analysed for occupation and exposure. RESULTS: Among 1972 patients, 66 (3.3%) reacted to DGEBF-R and 96 (4.9%) to DGEBA-R. Independent DGEBF-R allergies were seen in 5 patients only, and independent DGEBA-R allergies in 35. Specific exposure to DGEBF-R was found in 26 patients. The main occupational fields were the aircraft industry, the electrical and sports equipment industry, boat building, painting/floor coating, tile setting, and pipe relining. CONCLUSIONS: Independent contact allergies to DGEBF-R were rare, and screening with it was not found to be useful.

Occupational allergic contact dermatitis caused by coconut fatty acids diethanolamide.

BACKGROUND: Coconut fatty acids diethanolamide [cocamide diethanolamine (cocamide DEA)] is a surface-active derivative of coconut oil that is used in industrial, household and cosmetic products. Cocamide DEA contact allergy has been reported relatively seldom. OBJECTIVES: To describe cocamide DEA-positive patients in an occupational dermatology clinic. METHODS: We retrieved allergic reactions to cocamide DEA from test files, and studied the occupation, exposure, concomitant allergic reactions and diagnoses of the positive patients. RESULTS: Of the 2572 patients tested, 25 (1%) had an allergic reaction to cocamide DEA. Nineteen patients were occupational cases, and 11 worked in the metal industry. Hand cleansers constituted the main source of sensitization (n = 17). Other sources included two dishwashing liquids, one barrier cream, and one metalworking fluid. Three patients reacted to monoethanolamine and 2 to diethanolamine. Diethanolamine is an impurity of cocamide DEA, and can be found in cocamide DEA-containing products and in commercial patch test substances, which may explain some concomitant reactions. CONCLUSIONS: Cocamide DEA allergy is relatively common in patients with occupational hand dermatitis, and mainly derives from hand cleansers. However, exposure to detergents, metalworking fluids and barrier creams must also be taken into account. Concomitant reactions to ethanolamines are possible.

Occupational asthma, rhinitis, and contact urticaria caused by oxidative hair dyes in hairdressers.

BACKGROUND: Oxidative hair dyes commonly contain paraphenylene diamine (PPD) and its derivatives, a well-known cause of delayed hypersensitivity among both consumers and hairdressers. They are also considered possible causes of occupational respiratory diseases. Despite the widespread use of hair dyes, there are only a few reports of asthma, rhinitis, and contact urticaria caused by PPD and related compounds. OBJECTIVE: To characterize patients with occupational asthma, rhinitis, or contact urticaria associated with oxidative hair dyes and to evaluate the diagnostic methods. METHODS: We reviewed the patient files of the Finnish Institute of Occupational Health for the period January 1, 2001, through May 31, 2011, to identify patients diagnosed as having asthma, rhinitis, or contact urticaria associated with oxidative hair dyes. The diagnoses of asthma and rhinitis were based on specific inhalation challenges with hair dye products. Skin prick tests were performed with hair dye ingredients as hapten conjugates of human serum albumin and with hair dye products and ingredients as is. Open skin tests confirmed the diagnosis of contact urticaria. RESULTS: We describe 11 hairdressers with occupational asthma (5 cases), rhinitis (5 cases), and contact urticaria (3 cases) due to hair dyes. Of the 52 specific inhalation challenges performed, 9 (17%) had positive results. One patient who experienced an anaphylactic reaction when having her own hair dyed had positive skin prick test results to PPD and toluene-2,5-diamine sulfate. CONCLUSION: Hairdressers are at risk for occupational asthma, rhinitis, and contact urticaria due to oxidative hair dyes. Skin prick testing may be insensitive for detecting immediate hypersensitivity to PPD and related compounds.

Occupational contact allergy to monomeric isocyanates.

BACKGROUND: The monomeric isocyanates diphenylmethane diisocyanate (MDI), 2,4-toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) are used in polyurethane products and sometimes cause contact allergy. OBJECTIVES: To describe patients with isocyanate contact allergy in an occupational dermatology clinic. METHODS: Test files were screened for allergic reactions to isocyanates and 4,4'-diaminodiphenylmethane (MDA). Patients with allergic reactions to some of the allergens were analysed for occupation, exposure, concomitant reactions to other allergens, and diagnosis. RESULTS: Over a period of almost 13 years, 54 patients reacted to isocyanates (9 to IPDI, 12 to MDI, 6 to TDI, and 1 to HDI) or MDA (44 patients). The motor vehicle, electronics and paint industries, and painting and construction work, were among the most significant occupational fields. An in-house polymeric MDI (PMDI) test substance was superior to commercial MDI preparations. About half of the occupational cases related to MDI products were diagnosed by testing MDA. The most prominent cause of IPDI allergy comprised polyurethane paint hardeners. Some of the IPDI reactions could be explained by cross-allergy to isophoronediamine in epoxy products. Specific exposure to MDA was difficult to trace. CONCLUSIONS: MDA and PMDI test substances were significant in the diagnosis of MDI contact allergy.

Contact allergy to aliphatic polyisocyanates based on hexamethylene-1,6-diisocyanate (HDI).

BACKGROUND: Aliphatic polyisocyanates based on hexamethylene 1,6-diisocyanate (HDI) are components of lacquers, coatings, and spray paints. They are mainly composed of HDI trimers, but also contain larger oligomers, and minute amounts of HDI monomers (<1%). HDI trimers occur as biuret, isocyanurate and asymmetrical types. OBJECTIVES: We report on 4 patients with allergic contact dermatitis/contact allergy resulting from HDI-based polyisocyanates in polyurethane paints. METHODS: The patients were examined at the Finnish Institute of Occupational Health in 2000-2009. The first two patients were diagnosed by testing with their own polyurethane hardeners and ingredients of the hardeners. In 2002, HDI isocyanurate (HDI-IC) trimer was added to our isocyanate series, and the last two patients were screened with the series. RESULTS: Patient no. 1 was exposed and sensitized to HDI biuret trimer, patient no. 2 to HDI-IC trimer, and patient no. 4 to HDI asymmetrical trimer. Patient no. 3 was positive with HDI-IC trimer. He had been handling several paint hardeners containing HDI-based polyisocyanates, but the subtypes of the trimers remained unidentified. All 4 patients were negative with HDI monomer. CONCLUSIONS: HDI trimers are novel contact allergens in workers who handle polyurethane paints. The allergic reactions cannot be explained by sensitization to HDI monomer.

Occupational methacrylate and acrylate allergy--cross-reactions and possible screening allergens.

BACKGROUND: Acrylic resin monomers, especially acrylates and methacrylates, are important occupational allergens. AIMS: To analyse patterns of concomitant patch test reactions to acrylic monomers in relation to exposure, and to suggest possible screening allergens. PATIENTS/METHODS: We reviewed the patch test files for the years 1994-2009 at the Finnish Institute of Occupational Health for allergic reactions to acrylic monomers, and analysed the clinical records of sensitized patients. RESULTS: In a group of 66 patients allergic to an acrylic monomer, the most commonly positive allergens were three methacrylates, namely ethyleneglycol dimethacrylate (EGDMA), 2-hydroxyethyl methacrylate (2-HEMA) and 2-hydroxypropyl methacrylate (2-HPMA), and an acrylate, namely diethyleneglycol diacrylate (DEGDA). The patterns of concomitant reactions imply that exposure to methacrylates may induce cross-reactivity to acrylates, whereas exposure to acrylates usually does not lead to cross-allergy to methacrylates. Screening for triethyleneglycol diacrylate (TREGDA) in the baseline series was found to be useful, as 3 of 8 patients with diagnosed occupational acrylate allergy might have been missed without the screening. CONCLUSIONS: A short screening series of four allergens, EGDMA, DEGDA, 2-HPMA and pentaerythritol triacrylate (PETA), would have screened 93% of our 66 patients; each of the remaining 5 patients reacted to different acrylic monomer(s).

Contact allergy to epoxy (meth)acrylates.

BACKGROUND: Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. OBJECTIVE: To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. METHODS: We reviewed the 1994-2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. RESULTS: Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. CONCLUSIONS: The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA.