Contact allergy in Danish children: Current trends.

BACKGROUND: Contact allergy is common in children, but may be underdiagnosed. Importantly, the clinical relevance of specific allergies is subject to constant change, and it is therefore important to continuously monitor the trends and changes of contact allergies in the paediatric population. OBJECTIVES: To identify possible changes in contact allergy and allergic contact dermatitis among Danish children referred for patch testing. METHODS: A retrospective study was performed based on patch test data from the Danish National Database of Contact allergy. The current data were compared with previously published data on Danish children referred for patch testing. RESULTS: Between 2012 and 2016, 1573 children and adolescents were patch tested. Overall, 385 (24.5%) had at least 1 positive patch test reaction. The overall prevalence was similar in boys and girls, across age groups, and in patients with and without atopic dermatitis. Statistically significant increases in contact allergy to fragrances and isothiazoliones were seen, whereas a decrease in nickel allergy was found. CONCLUSION: Allergic contact dermatitis continues to be a common disease in children, and is even significantly increasing for some allergens.

Occupational contact dermatitis in hairdressers: an analysis of patch test data from the Danish contact dermatitis group, 2002-2011.

BACKGROUND: Occupational contact dermatitis among hairdressers is frequent, owing to daily exposure to irritants and allergens. OBJECTIVES: To identify sensitization to the most common allergens associated with the occupation of hairdressing. METHODS: Patch test results of 399 hairdressers and 1995 matched controls with contact dermatitis, registered by the Danish Contact Dermatitis Group between January 2002 and December 2011, were analysed. All patients were patch tested with the European baseline series, and hairdressers were additionally tested with the hairdressing series. RESULTS: Occupational contact dermatitis (p < 0.001) and hand eczema (p < 0.001) were observed significantly more often among hairdressers than among controls. Atopic dermatitis was less commonly observed among hairdressers (21.3%) than among controls (29.4%) (p < 0.01). Allergens from the European baseline series with a statistically significant association with the occupation of hairdressing were p-phenylenediamine, thiuram mix, and benzocaine. Frequent sensitizers from the hairdressing series were ammonium persulfate, toluene-2,5-diamine, 3-aminophenol, and 4-aminophenol. Cysteamine hydrochloride and chloroacetamide emerged as new sensitizers. CONCLUSIONS: These results indicate a healthy worker effect among hairdressers diagnosed with eczema. Ammonium persulfate and p-phenylenediamine remain frequent sensitizers in hairdressers with contact dermatitis. Cysteamine hydrochloride and chloroacetamide should be included in future surveillance studies.

Occupational contact dermatitis in blue-collar workers: results from a multicentre study from the Danish Contact Dermatitis Group (2003-2012).

BACKGROUND: Blue-collar workers have a high risk of occupational contact dermatitis, but epidemiological studies are scarce. OBJECTIVES: To investigate allergic contact dermatitis in blue-collar workers with dermatitis registered by the Danish Contact Dermatitis Group. METHODS: A retrospective analysis of patch test data from 1471 blue-collar workers and 1471 matched controls tested between 2003 and 2012 was performed. A logistic regression was used to test for associations. RESULTS: The blue-collar workers often had occupational hand dermatitis (p < 0.001). Atopic dermatitis was less commonly observed among blue-collar workers (19.6%) than among controls (23.9%) (p = 0.005). Allergens with a statistically significant association with the occupational group of blue-collar workers were epoxy resins, methyldibromo glutaronitrile, 2-bromo-2-nitro-1,3-propanediol, potassium dichromate, and methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI). The following occupations were additionally identified as risk factors for contact sensitization to MCI/MI and MI, epoxy resins, and potassium dichromate, respectively: painting, construction work, and tile setting/terrazzo work. CONCLUSION: Contact allergy is a major problem among blue-collar workers. The data indicate a healthy worker effect among blue-collar workers diagnosed with dermatitis, as blue-collar workers were diagnosed significantly less often with atopic dermatitis than were controls.

Occupational contact dermatitis in painters: an analysis of patch test data from the Danish Contact Dermatitis Group.

BACKGROUND: Painters are among the occupational groups that most commonly experience occupational contact dermatitis, but few investigations exist concerning this occupation. OBJECTIVES: To characterize painters with contact dermatitis and identify the most common allergens associated with the occupation. Materials and methods. All patch test results of 219 painters and 1095 matched controls registered by the Danish Contact Dermatitis Group between 2001 and 2010 were analysed. RESULTS: Hand eczema (p < 0.0001) and occupational contact dermatitis (p < 0.0001) were observed significantly more often in the painters than in the group of controls. Sensitizations to the following allergens from the European baseline series were associated with the occupation and were statistically significant: methylchloroisothiazolinone/methylisothiazolinone, epoxy resin, formaldehyde, and quaternium-15. Three different isothiazolinones emerged as the most frequent sensitizers of the allergens tested in addition to the baseline series. CONCLUSIONS: The results indicate that painters have an increased risk of developing occupational hand eczema. Isothiazolinones and epoxy resin proved to be the two most frequent sensitizers in painters.