Ann Pontén

Comparison of three different techniques for application of water solutions to Finn Chambers

Background: With regard to contact allergy, the dose of a sensitizer per unit skin area is an important factor for both sensitization and elicitation, and therefore a known amount/volume of test preparation should be applied at patch testing.

Occupational allergic contact dermatitis in a company manufacturing boards coated with isocyanate lacquer.

Over a short period of time, there was an outbreak of work‐related skin lesions among workers at a company producing flooring laminate boards, after the introduction of a water‐repellent lacquer based on diphenylmethane‐4,4′‐diisocyanate (MDI). In 5 workers, patch testing was performed with a standard series, an isocyanate series and work‐environmental products when indicated. 3 of the workers were tested with the lacquer, and contact allergy was found with concurrent reactions to 4,4′‐diaminodiphenylmethane (MDA). 1 of the 3 workers also showed a simultaneous reaction to MDI, whereas 1 showed a positive reaction to dicyclohexylmethane‐4,4′‐diisocyanate (HMDI). Of the 2 individuals not tested with the lacquer, 1 reacted to both MDI and MDA, whereas the other reacted to a soap used at work. In 3 of 4 cases, the isocyanate reactions appeared after D3. Occupational contact with isocyanates should not exclusively be focused upon respiratory hazards, as this report shows that skin contamination probably increases the risk of developing contact allergy to isocyanates and isocyanate‐related substances. When aiming at diagnosing contact allergy to isocyanates, it is desirable to perform a late reading, as positive reactions appear late. MDA appears to be a good marker for isocyanate hypersensitivity.

Occupational dermatoses in a metalworking plant

In a plant producing advanced components for engines and drivelines we undertook a survey of occupational dermatoses, based on a questionnaire, clinical examination, and patch testing with a standard series and a series of samples from the working environment. The questionnaire was given to all 430 employees and it was answered and returned by 382 of these. 214 reported having had or having skin manifestations during the time of employment suspected of being work‐related. 183 employees (164 metal workers, 19 office staff) participated in the clinical investigation, 182 (163 metal workers, 19 office staff) being patch tested. Occupational dermatoses were diagnosed in 23 of these 163 (14.1%) and in 1 of these 19 (5.3%). In all, irritant contact dermatitis was diagnosed in 12 metal workers, occupational allergic contact dermatitis in 11 (10 metal workers and 1 office clerk) and folliculitis in 1 metal worker. In the 11, neat oils were the cause in 4 workers, a water‐based cutting fluid in 3 and various biocides in 4.

Occupational allergic contact dermatitis caused by sterile non-latex protective gloves: clinical investigation and chemical analyses.

Background An increased frequency of occupational contact hand dermatitis among surgical operating theatre personnel has been noticed.

Formaldehyde in reusable protective gloves.

Due to the clinical findings in a single patients case, formaldehyde was suspected to be present in clinically relevant levels in reusable protective gloves. Therefore, 9 types of gloves were investigated with the semi‐quantitative chromotropic acid method. It was found that 6/9 gloves emitted some formaldehyde and that 4/9 gloves emitted ≥40 µg of formaldehyde. Most of the formaldehyde was found on the inside of the gloves. To get an indication of the clinical relevance, a comparison with a protective cream declared to contain the formaldehyde‐releasing agent diazolidinyl urea was performed by comparing areas of gloves with areas of cream layers with thickness 1–2 mg/cm2. It was found that the amounts of formaldehyde emitted from the gloves might be in the same range as emitted from a layer of cream.

Reaction profile in patch testing with allergens formed during vulcanization of rubber

Vulcanization of rubber changes its allergen pattern.

Epoxy-based production of wind turbine rotor blades: occupational contact allergies.

BACKGROUND An industry producing rotor blades for wind turbines with an epoxy-based technology had experienced an increasing number of workers with dermatitis, among whom the frequency of occupational contact allergy (OCA) was suspected to be underestimated. OBJECTIVE To investigate the frequency of OCA by patch-testing with a specially profiled occupational patch test series. METHODS In a blinded study design, 603 workers were first interviewed and thereafter clinically examined. Based on a history of work-related skin disease, clinical findings of dermatitis, or both, 325 (53.9%) of the workers were patch-tested with an occupational patch test series and the European Standard patch test series. RESULTS Of the 603 investigated workers, 10.9% had OCA and 5.6% had contact allergy to epoxy resin in the standard test series. Contact allergy to amine hardeners/catalysts was found in 4.1% of the workers. Among the workers with OCA, 48.5% reacted to work material other than epoxy resin in the European Standard patch test series. CONCLUSION Approximately 50% of the workers with OCA would not have been detected if only the European Standard patch test series had been used.

Clinically relevant contact allergy to formaldehyde may be missed by testing with formaldehyde 1·0%

Background  It has been found that patch testing with 15 μL formaldehyde 2·0% aq. detects twice as many allergies as by testing with 1·0%. The clinical relevance of positive patch test reactions is often difficult to determine. Repeated open application tests are simple to do and help to evaluate the significance of patch test results.

Concomitant contact allergy to the resins, reactive diluents and hardener of a bisphenol A/F-based epoxy resin in subway construction workers

An outbreak of suspected contact dermatitis among subway construction workers was suspected to be due to a new bisphenol A/F‐based epoxy resin system (ERS). The construction workers used ERSs during the insertion of iron bars into concrete walls. The objective of the study was to determine the components (if any) of the ERS responsible for the contact allergy. Patch testing was performed on 20 of the 22 construction workers who had had contact with the ERS, and to the various subcomponents of component A on 5 of the 7 who reacted to this component. 9 patients (9/22, 40.9%) had clinical symptoms and signs of suspected contact dermatitis at presentation. 7 of these 9, but none of the 11 asymptomatic individuals, were positive to component A, while all were negative to component B. Of the 5 cases receiving further patch testing, all reacted to m‐xylylene diamine, 4 to 1,6‐hexanediol diglycidyl ether, 3 to epoxy resins of the bisphenol F‐type and trimethylolpropane triglycidyl ether 0.25% petrolatum, and only 1 to epoxy resins of the bisphenol A‐type. Contact allergy to ERSs may involve hardeners and diluents as well as resins, and patch testing for reaction to all components should be performed.

Epoxy-based production of wind turbine rotor blades: occupational dermatoses.

Occupational dermatoses were investigated in a factory producing rotor blades for wind turbines by an epoxy‐based process. In a blinded study design, 603 workers were first interviewed and thereafter clinically examined. Based on a history of work‐related skin disease, clinical findings of dermatitis, or both, 325 (53.9%) of the workers were patch tested with a specially profiled occupational patch‐test series and the European standard patch‐test series. Calculated on all investigated workers, 17.1% of the workers were diagnosed with occupational dermatoses caused by work. Occupational allergic contact dermatitis was found in 10.9% of the workers. The estimated frequency of irritant contact dermatitis caused by work was 6.1%. Dermatitis on the hands was associated with contact allergy to epoxy resin (P = 0.017). The number of days on leave before the clinical examination was negatively associated with the presence of dermatitis (P = 0.001). Among workers employed 7–12 months, the frequency of occupational contact allergy was higher than that among workers employed for ≤6 months (P = 0.004). Females both washed their hands more often (P < 0.001) and used more moisturizers/protection creams at work (P < 0.001) than males. No sex differences were found concerning dermatitis on the hands.