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.

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 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.

Short-term prognosis of occupational asthma in a Finnish population.

BACKGROUND: Causative agents of occupational asthma (OA) are well described in literature but far less is known about factors affecting the outcome of OA. Short duration of exposure, early diagnosis when symptoms appear and further avoidance of exposure have been suggested as good prognostic factors. This study was designed to investigate a short-term outcome of OA. METHODS: The medical records of 47 Caucasian patients from a Finnish population diagnosed with OA in year 2003 were reviewed retrospectively. Employment status at 6-month follow-up of all patients was determined. We assessed the following potential predictors of unemployment at follow-up: the causative agents of OA, asthma medication, spirometry results, smoking status, gender, age, occupation, atopy status, bronchial hyperresponsiveness and time to diagnosis. We calculated odd ratios (ORs) to predict employment status at follow-up. RESULTS: At the follow-up examination, 23 persons (49%) were not working. At the time of follow-up there were no significant differences in pulmonary function between those employed and those who discontinued to work. Atopy at baseline predicted diminished lung function at the 6-month follow-up. In addition, atopy was the only prognostic factor and was inversely related to the work discontinuation at the follow-up [OR 0.18, 95% confidence interval (CI) 0.04-0.79]. Work continuation as an OA outcome at 6 months could not be predicted by gender, age, occupational status, exposure antigen, smoking habits or duration of symptoms before diagnosis. CONCLUSIONS: The socio-economic short-term prognosis of OA was relatively poor since half of the patients were not at work at the 6 months follow-up.

Occupational contact urticaria caused by cyclic acid anhydrides.

BACKGROUND: Cyclic acid anhydrides often cause allergic respiratory diseases, but contact urticaria because of these anhydrides has been considered rare. OBJECTIVE: We describe 21 patients diagnosed with occupational contact urticaria at the Finnish Institute of Occupational Health during the period 1990-2006. METHOD: Prick test with human serum albumin (HSA)-acid anhydride conjugates, determination of specific immunoglobulin E (IgE), and open application were used in the diagnosis. RESULTS: 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. CONCLUSIONS: 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.

Audit of quality of diagnostic procedures for occupational asthma.

BACKGROUND: Previous studies have reported deficiencies in the quality of the diagnosis of occupational asthma. A low quality of diagnostic procedures means that the occupational cause of asthma is less likely to be revealed. AIMS: To assess the current quality of the diagnosis of occupational asthma before referral to a specialist occupational medicine centre. METHODS: The quality of diagnostic procedures was assessed by reviewing the files of 150 patients who were referred to the Finnish Institute of Occupational Health in 2003 with a suspicion of an occupational cause of their asthma. The quality indicators used were assessment of workplace exposures, spirometric studies, bronchodilator response, serial workplace measurements of peak expiratory flow (PEF) and the time since first symptoms to the final diagnosis. For each indicator, criteria to differentiate between sufficient and insufficient care were developed. RESULTS: Exposure assessments, spirometric studies and bronchodilator responses were performed in 92, 87 and 79% of cases in the total study group, respectively. Workplace measurements of PEF had been performed in 51% of the cases, and the quality of measurements was sufficient in 52%. Workplace exposures had been assessed significantly more often in occupational health care than in other health care units. The median time from the beginning of symptoms to the final diagnosis was 3.2 years. CONCLUSIONS: Although the diagnostic procedures were mostly of sufficient quality, the performance of serial measurements of PEF at the workplace and the time to diagnosis should be substantially improved.