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| 2. |
- Dahlin, Jakob, et al.
(författare)
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Chemical burns caused by trifluoroacetic acid.
- 2013
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 69:3, s. 176-180
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Tidskriftsartikel (refereegranskat)abstract
- Trifluoroacetic acid is a very strong carboxylic acid. The acid has been suspected to have similar toxic effects as hydrofluoric acid on skin contact. Hydrofluoric acid is highly toxic, owing to skin penetration by fluoride ions. A spill of hydrofluoric acid on the skin may be fatal. As trifluoroacetic acid contains fluorine, patients with chemical burns caused by trifluoroacetic acid have been given particular attention when treated in the hospital.
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| 3. |
- Engfeldt, Malin, et al.
(författare)
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Chemical analysis of 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate and isophorone diisocyanate in petrolatum patch-test preparations.
- 2005
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Ingår i: Dermatitis. - 1710-3568. ; 16:3, s. 130-135
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Tidskriftsartikel (refereegranskat)abstract
- Background: Isocyanates with the general formula R-(N=C=O) are theoretically contact sensitizers. However, allergic contact dermatitis (ACD) from isocyanates is seldom reported. In previous reports, patients reacted to their isocyanate-based work materials but not to commercial patch-test preparations of isocyanates. Therefore, we suspected that the low frequency of reported ACD from isocyanates was partly due to inadequate commercial preparations. A past study also showed the concentrations of diphenylmethane-4,4'-diisocyanate (4,4'-MDI) in petrolatum preparations to be much lower than declared. Objective: In this study, 2,4-toluene diisocyanate (2,4-TDI), 1,6-hexamethylene diisocyanate (1,6-HDI), and isophorone diisocyanate (IPDI) were investigated in a similar fashion. Methods: In preparations from 12 dermatology departments and two suppliers of patch-test allergens, we determined the isocyanate content as the isocyanate-dibutylamine derivative, using liquid chromatography and mass spectrometry. The preparations were considered stable if the ratio between the stated and found concentrations was within the range of 0.8 to 1.2. Results: Although 28 of 36 investigated preparations had ratios outside of the stable range, they were in its vicinity, which indicates that preparations of 2,4-TDI, 1,6-HDI, and IPDI are more stable than are preparations of 4,4'-MDI where previously reported results showed ratios far outside of stable range. Conclusion: As opposed to preparations of 4,4'-MDI, preparations of 2,4-TDI, 1,6-HDI, and IPDI can be considered to be stable.
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| 4. |
- Engfeldt, Malin, et al.
(författare)
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How to optimize patch testing with diphenylmethane diisocyanate
- 2007
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 57:3, s. 138-151
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that patch test preparations of polymeric diphenylmethane diisocyanate (PMDI) are more stable than preparations of diphenylmethane-4,4'-diisocyanate (4,4'-MDI). This study was conducted to (i) investigate whether PMDIs yield as many positive reactions as 4,4'-MDI, (ii) study concurrent reactions to 4,4'-MDI and 4,4'-diaminodiphenylmethane (4,4'-MDA), and (iii) follow the course of positive reactions during 4 weeks. It was shown that PMDIs detect as many positive reactions as 4,4'-MDI. Thus, they are better patch test agents being more stable than preparations of 4,4'-MDI. We recommend that PMDIs with a monomer content of at least 35% is used in 2.0% petrolatum (pet.) (i.e. monomer patch test concentration approximately 0.7%). It was shown that reactions to 4,4'-MDI and PMDIs appear late and we recommend readings on both day (D) 3/4 and D7. 4,4'-MDA was shown to be a good marker for 4,4'-MDI and patch testing with 4,4'-MDA in 0.25% pet. can be used instead of PMDI. Concomitant reactions to 4,4'-MDI and 4,4'-MDA are probably not caused by conversion of 4,4'-MDI into 4,4'-MDA by reaction with water. Another explanation is a path of reactions leading to ureas and MDI conjugates with skin constituents, which are hydrolysed into 4,4'-MDA. This complex process depends upon several factors and might explain why positive MDI reactions appear after D7.
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| 5. |
- Engfeldt, Malin, et al.
(författare)
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Is it possible to improve the patch-test diagnostics for isocyanates? A stability study of petrolatum preparations of diphenylmethane-4,4'-diisocyanate and polymeric diphenylmethane diisocyanate.
- 2007
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 56:1, s. 27-34
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that the concentration of diphenylmethane-4,4'-diisocyanate (4,4'-MDI) in commercial test preparations was so low that patch testing with the same was not reliable. The stability of 4,4'-MDI in petrolatum (pet.) was compared with pet. preparations of polymeric diphenylmethane diisocyanate (PMDI), which consists of a complex mixture of monomeric isomers and oligomers of MDI. Preparations of 4,4'-MDI and PMDI were stored under 3 different conditions, i.e. at room temperature, refrigerated and frozen. They were analysed continuously during 1 year with regard to the content of 4,4'-MDI, 3-ring oligomers and 4-ring oligomers using liquid chromatography-mass spectrometry. PMDI preparations kept frozen were stable for a year. All other preparations failed to fulfil the requirements of stability, i.e. +/- 20% of the initial concentration. Storage in a freezer prolonged the lifetime for 4,4'-MDI. The decrease in concentration for preparations kept at room temperature and refrigerated was less rapid in PMDI preparations than in 4,4'-MDI preparations. PMDI preparations are better suited for patch testing patients exposed to MDI because they are more stable and homogeneous than 4,4'-MDI preparations. They better reflect possible allergens that workers are exposed to because products used in industry contain both monomers and oligomers.
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| 6. |
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| 7. |
- Engfeldt, Malin, et al.
(författare)
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Several cases of work-related allergic contact dermatitis caused by isocyanates at a company manufacturing heat exchangers.
- 2013
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 68:3, s. 175-180
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Tidskriftsartikel (refereegranskat)abstract
- Background. A 43-year-old woman was referred by her occupational health service with suspected occupational contact dermatitis. In connection with the investigation, a workplace visit was undertaken at her company, which used an adhesive based on pre-polymeric diphenylmethane diisocyanate in one of its units. During the visit, we became aware of six other employees with skin problems who were then referred to our department for investigation. Objectives. To investigate the seven employees complaining about skin problems. Methods. Seven employees were patch tested with a baseline series, an isocyanate series, and a series with work material. Results. Five of seven patients had occupational contact allergy. Four reacted to isocyanate-related test preparations, and one to a cleanser used at the workplace. Conclusions. Workplace visits constitute an important part of an occupational investigation, as they might give a broader picture of the problems at a company. In this case, it was found that 5 of 100 employees currently had or had previously had occupation-related skin problems. Owing to 'healthy worker selection', some of these patients might have been missed if we had not performed a full-scale workplace visit.
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| 8. |
- Engfeldt, Malin, et al.
(författare)
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The outcome of 9 years of consecutive patch testing with 4,4'-diaminodiphenylmethane and 4,4'-diphenylmethane diisocyanate.
- 2013
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 68:2, s. 98-102
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Tidskriftsartikel (refereegranskat)abstract
- Background: Two outbreaks of allergic contact dermatitis caused by isocyanates at two companies in southern Sweden initiated a research project focusing on contact allergy to isocyanates. Within the project, there was an interest in determining how often contact allergy to the most common isocyanate, diphenylmethane-4,4'-diisocyanate (4,4'-MDI), occurred. Objectives: To determine and compare the occurrence of contact allergy to 4,4'-MDI, its corresponding amine 4,4'-diaminodiphenylmethane (4,4'-MDA), and polymeric diphenylmethane diisocyanate (PMDI) in a Swedish and a Belgian study population. Patients and method. The study population consisted of 6190 consecutively patch tested dermatitis patients: 5690 patients from Malmö, Sweden, and 500 patients from Leuven, Belgium. Patch test results were analysed and compared. Results. None of the Belgian patients reacted positively to 4,4'-MDI, but 5 Swedish patients did. Contact allergy to 4,4'-MDA was more common in the Belgian patients than in the Swedish patients: 3.6% and 0.9%, respectively. This could possibly be explained by the fact that the prevalence of p-phenylenediamine allergy was higher in the Belgian population. Conclusions: The prevalence of contact allergy to 4,4'-MDI, 4,4'-MDA and PMDI is not high enough to justify their inclusion in any baseline series. Isocyanate allergic individuals should be detected by aimed testing with isocyanate series and work materials.
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| 9. |
- Goon, Anthony, et al.
(författare)
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Correlation between Stated and Measured Concentrations of Acrylate and Methacrylate Allergens in Patch-Test Preparations
- 2011
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Ingår i: Dermatitis. - : Mary Ann Liebert Inc. - 1710-3568. ; 22:1, s. 27-32
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Tidskriftsartikel (refereegranskat)abstract
- Background: Contact allergy to acrylates and methacrylates is not uncommon. The allergy is confirmed by patch-testing patients with commercial patch-test preparations. Objective: To investigate acrylate and methacrylate allergens used for patch testing in nine different dermatology departments from Europe, America, Asia, and Australia. Methods: The acrylate and methacrylate (methyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, ethylene glycol dimethacrylate, and triethylene glycol diacrylate) allergen samples were analyzed with high-performance liquid chromatography to measure the allergen content. Results: Variation in measured versus stated concentrations was seen in these samples. The ratio of measured to stated concentrations ranged from 0.11 to 1.1. Only 22 (63%) of 35 samples were within the arbitrary acceptable limits of 80 to 120% of the stated concentrations. Conclusion: The results may have implications for individual diagnosis and prevention and when test results from various centers are compared.
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