[show abstract][hide abstract] ABSTRACT: 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.
To describe patients with isocyanate contact allergy in an occupational dermatology clinic.
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.
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.
MDA and PMDI test substances were significant in the diagnosis of MDI contact allergy.
[show abstract][hide abstract] ABSTRACT: Acrylic resin monomers, especially acrylates and methacrylates, are important occupational allergens.
To analyse patterns of concomitant patch test reactions to acrylic monomers in relation to exposure, and to suggest possible screening allergens.
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.
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.
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).
[show abstract][hide abstract] ABSTRACT: 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.
We report on 4 patients with allergic contact dermatitis/contact allergy resulting from HDI-based polyisocyanates in polyurethane paints.
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.
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.
HDI trimers are novel contact allergens in workers who handle polyurethane paints. The allergic reactions cannot be explained by sensitization to HDI monomer.
[show abstract][hide abstract] ABSTRACT: 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.
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.
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.
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.
[show abstract][hide abstract] ABSTRACT: Cyclic acid anhydrides often cause allergic respiratory diseases, but contact urticaria because of these anhydrides has been considered rare.
We describe 21 patients diagnosed with occupational contact urticaria at the Finnish Institute of Occupational Health during the period 1990-2006.
Prick test with human serum albumin (HSA)-acid anhydride conjugates, determination of specific immunoglobulin E (IgE), and open application were used in the diagnosis.
The majority of the patients worked in the manufacture of electrical machines and were exposed to an epoxy hardener containing methyl hexahydrophthalic anhydride. The largest prick test reaction was often noted for the acid anhydride the patient had been exposed to. The specific IgE results were mostly in line with the prick test reactions. Phthalic anhydride IgE was determined in 20 patients and was found positive in 19 patients. In open application, a positive test result often required the use of the undiluted hardener.
Contact urticaria may be more common than previously believed. Prick tests with HSA-acid anhydride conjugates were a useful test method for detecting immediate sensitization to acid anhydrides. The determination of the specific IgE gave almost equal results. The open application test often had to be performed with the undiluted anhydride product to obtain a positive test result.
[show abstract][hide abstract] ABSTRACT: Formaldehyde allergy is common and usually derives from formaldehyde-releasing biocides in cosmetic and other products.
To analyse patterns of patch test reactions to formaldehyde and formaldehyde-releasing compounds and the sources of sensitization.
At the Finnish Institute of Occupational Health, we screened the patch test files for allergic reactions to formaldehyde and 12 formaldehyde-releasing compounds. All patients with contact allergy to any of the substances were included, and their records were reviewed.
Between January 2001 and May 2007, we had patch tested 81 patients with formaldehyde allergy and 18 with independent allergy to some formaldehyde releaser. Of the formaldehyde allergies, 60 were new sensitizations, 25 of which were considered to be occupational. The most common source of occupational sensitization was metalworking fluids followed by creams and related products. Exposure to formaldehyde-releasing preservatives in liquid soaps and other rinse-off products was common in both occupational and non-occupational cases. Reactions to formaldehyde-releasing compounds were seen in 79% of the formaldehyde-allergic patients.
Occupational formaldehyde allergy was common and occurred in metalworkers, hairdressers, masseurs, and workers using protective creams, detergents, and liquid soaps. When compared with studies on general dermatological patients, contact allergy to formaldehyde releasers without formaldehyde allergy was rare.
[show abstract][hide abstract] ABSTRACT: Epoxy resins (ERs) are used in paints and other protective coatings, including flooring materials. Bisphenol A diglycidyl ether (BADGE) ERs (BADGE ERs) account for about 75% of the ERs used world-wide. ERs can cause both immediate and delayed allergic reactions, but immediate reactions are rare.
Occupational asthma (OA) was diagnosed on the basis of a specific challenge test combined with the patient's history of occupational exposure and respiratory symptoms.
A 39-year-old nonsmoking construction worker experienced dyspnea when laying ER-containing floors, but not in other situations. He also presented skin symptoms. IgE-mediated allergy to BADGE ER could be verified with both serum IgE antibodies and skin prick tests. The specific bronchial challenge test with BADGE ER caused an immediate asthmatic reaction. On patch testing, a positive reaction was provoked by BADGE ER.
This is the first study on a patient exposed to BADGE ER with IgE-mediated immediate OA, based on a positive inhalation challenge test. If work-related respiratory symptoms develop when handling ERs, the possibility of OA should be recognized.
International Archives of Allergy and Immunology 09/2008; 148(1):41-4. · 2.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: Glues and sealants are important causes of methacrylate and acrylate allergy.
This study aimed to analyse patterns of allergic patch test reactions to acrylic monomers in relation to exposure in patients sensitized from glues.
We screened the patch test files at the Finnish Institute of Occupational Health from 1994 to 2006 for allergic reactions in the 'Methacrylate series' and analysed the clinical records of sensitized patients. Only patients who had handled acrylic glues at work were included.
10 patients had allergic reactions to acrylic monomers and had been sensitized from glues at work. 9 of them had used anaerobic sealants, 3 cyanoacrylate-based instant adhesives, and 1 patient a bi-component instant adhesive. All the patients reacted to 2-hydroxyethyl methacrylate (2-HEMA) and ethyleneglycol dimethacrylate (EGDMA); reactions to 2-hydroxypropyl methacrylate, triethyleneglycol dimethacrylate, and tetrahydrofurfuryl methacrylate were also common. The first 4 methacrylates were found in the glues used by the patients. Ethyl cyanoacrylate (ECA) gave no reactions, but 1 patient reacted weakly to her own ECA-based glue.
2-HEMA and EGDMA are good screeners for contact allergy to anaerobic sealants and also detected a single case deriving from bi-component acrylic glue.
[show abstract][hide abstract] ABSTRACT: Industrial lubricants are usually made of petroleum and contain no water. Industrial greases and neat oils (insoluble metalworking oils) cause contact allergy relatively seldom, and reported allergies to the components of engine oils, such as hydraulic oils, are extremely scarce.
The aim was to describe patients with contact allergy to the components of industrial lubricants.
We describe 2 patients with allergic reactions to 2,5-dimercapto-1,3,4-thiadiazole. Their allergies derived from guide-way oil and grease. Guide-way oils are lubricants for metalworking machines. Machinists may have continuous skin contact to these oils, as the oils are leaked to the circulating metalworking fluid system and form the so-called 'tramp oil'. We also report a new case with allergy to phenyl-alpha-naphtylamine in grease.
2,5-Dimercapto-1,3,4-thiadiazole is an aromatic compound used in oils and greases. It has previously caused contact allergy to workers who have handled the pure chemical, but to our knowledge, there are no previous reports of contact allergy from products containing the chemical in a relatively low concentration. 1 of our 2 cases had been sensitized from grease and the other from a guide-way oil. The latter case shows that machinists may become sensitized to lubricants that leak to the metalworking fluid system.
[show abstract][hide abstract] ABSTRACT: Methacrylates are important allergens in dentistry.
The study aimed to analyse patch test reactivity to 36 acrylic monomers in dental personnel in relation to exposure.
We reviewed the test files at the Finnish Institute of Occupational Health from 1994 to 2006 for allergic reactions to acrylic monomers in dental personnel and analysed the clinical records of the sensitized patients.
32 patients had allergic reactions to acrylic monomers: 15 dental nurses, 9 dentists, and 8 dental technicians. The dentists and dental nurses were most commonly exposed to 2-hydroxyethyl methacrylate (2-HEMA), triethyleneglycol dimethacrylate (TREGDMA), and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA). 8 dentists and 12 dental nurses were allergic to 2-HEMA. The remaining dentist was positive to bis-GMA and other epoxy acrylates. The remaining 3 dental nurses reacted to diethyleneglycol diacrylate (DEGDA) or triethyleneglycol diacrylate (TREGDA), but not to monofunctional and multifunctional methacrylates. Our dental technicians were mainly exposed and sensitized to methyl methacrylate (MMA) and ethyleneglycol dimethacrylate (EGDMA). 1 technician reacted only to 2-HEMA, and another to ethyl methacrylate (EMA) and ethyl acrylate (EA).
2-HEMA was the most important allergen in dentists and dental nurses, and MMA and EGDMA in dental technicians. Reactions to bis-GMA, DEGDA, TREGDA, EMA and EA were relevant in some patients.
[show abstract][hide abstract] ABSTRACT: 2-N-octyl-4-isothiazolin-3-one (OIT) is an antimicrobial agent that is mainly used in industrial settings. The objective of the study was to find the significance of OIT contact allergy at our clinic of occupational dermatology. We looked through our patient material from 1991 for allergic reactions to OIT and analysed the clinical records. We found 8 patients with ordinary allergic reactions to OIT and 1 late reaction. 2 workers in the manufacture of paints had occupational allergic contact dermatitis from OIT in biocides. 2 patients were machinists and 3 were female farmers: in these cases, however, we could not find any exposure. A sewing machine operator had patch test reactions to 2 of her mattress textiles, and chemical analysis of them showed 40-50 parts per million OIT. In conclusion, OIT is a rare sensitizer, and its contact allergies occur mainly in paint manufacturing. It is infrequently used in metal-working fluids and possibly sensitizes machinists. Although it is also used in some biocides recommended for use in the textile industry, there are no previous reports of contact allergy in this field. Our sewing machine operator with OIT contact allergy had probably been sensitized from mattress textiles.
[show abstract][hide abstract] ABSTRACT: Late patch test reactions on day (D) 10-14, which on subsequent retesting appear in the normal time schedule on D2-D4, indicate active sensitization due to the patch test. The objective of this study was to report our series of late patch test reactions. We analysed the clinical records of all the patients who had reported late reactions for the date of the late reaction, the results of the first patch tests and retesting. Between January 2002 and February 2006, we had a total of 16 patients with late reactions (>or=D10). 12 of them were retested. Retesting confirmed active sensitization to 1 or more allergens in 11 patients (1.3% of 884 patients patch tested). In these 11 cases, none of the late reactions had clear relevance to the symptoms before its appearance. The commonest allergens were paraphenylenediamine (PPD) in 6 patients (0.72% of 826 PPD tests), elecampane (Inula helenium) and black-eyed Susan (Rudbeckia sp. hybr.) extracts in 3 patients, and 4-aminoazobenzene and Disperse Orange 3 in 2 patients. The late reaction did not generally affect the clinical course. Only 1 patient developed new dermatitis possibly due to active sensitization. Late reactions meeting the classic criteria of active sensitization were relatively common in our series from a special clinic of occupational dermatology.