Substitution as a measure to prevent occupational skin diseases; occupational contact allergy network (OCA-network)

Status:

completed 05/2011

Aims:

Substitution of sensitizing substances is a possible way to prevent occupational allergic contact dermatitis. For this purpose, recognizing the responsible allergens is a necessary prerequisite. Hence, meaningful allergy diagnostics is obligatory. Routine diagnostics comprise standardized patch test series, which by far do not represent the current spectrum of occupational allergens. Therefore, patch testing with products from the patient’s workplace and their ingredients is absolutely necessary. However, this remains undone in many cases due to a lack of time and specific knowledge.

Activities/Methods:

The network "occupational contact allergy" (OCA-network) offered help to inquiring physicians concerning information on occupational products and their ingredients and provisioning of raw materials for patch testing. Additionally, the OCA-network gave advice concerning suitable patch test concentrations and vehicles.

After adequate preparation, inquiries concerning 255 patients from 98 different occupations were processed during the study period (01.04.2008 – 31.05.2011). Altogether, 1.380 occupational products and 1.788 ingredients were assessed allergologically concerning suitable patch test conditions. Patch testing was declined in 352 products and 557 ingredient substances, due to various reasons. Altogether, 2.607 recommendations for patch test concentrations and vehicles for 2.259 products and ingredients were given. Not more than 7% of these recommendations were covered by standardized patch test preparations, while 93% of the recommended preparations had to be prepared for the individual patient.

At the end of the project, patch test results of 169 patients were available. In only 19 cases, recommendations of the OCA-network were completely implemented. In 98 patients, ingredients of occupational products, of which no patch test preparation was commercially available, were patch tested. In all, only 28% of the patch test recommendations were realized in the patients concerned. According to the main clientele of the clinics and statutory accident insurances actively taking part in the project, many inquiries concerned epoxy resin products, denture materials, lacquers and disinfectants. Cooperativeness of the producers of the occupational products was very varying and rather unsatisfactory, on the whole.

Results:

Altogether, 432 patch tests with ingredient substances of the occupational products (without commercially available patch test preparations) were done. In these tests, 21 positive reactions (5%) were seen in 17 patients (17% of 98). Among others, there were reactions to Didecyldimonium chloride (CAS Nr. 7173-51-5), Laurylamine dipropylenediamine (CAS Nr. 2372-82-9), Cocospropylenediamine-1,5-bis-guanidiniumdiacetate (CAS Nr. 85681-60-3), 1-Decanaminium, N-Decyl-N-(2-hydroxyethyl)-N-methyl-, propanoate (salt) (CAS Nr. 107879-22-1) and N-Dodecylpropane-1,3-diamine (CAS Nr. 5538-95-4) in the field of surface and instrument disinfectants. Among the ingredients of epoxy resin products, a reaction was found to 2,4,6-Tris(dimethylaminomethyl)phenol (CAS Nr. 90-72-2), and a reaction to (Ethylenedioxy)dimethanol (CAS Nr. 3586-55-8) was seen among ingredients of metalworking fluids. Patch test recommendations (concentration and vehicle) for ingredient substances developed in the course of the project were provided to the statutory accident insurances as an excel document for further utilization. The file comprises 1.218 recommendations for 956 different substances. In addition, substances, which were part of the inquiries to the OCA-network, and which were not recommended for patch testing, were compiled in the excel document.

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