Publications by authors named "Niels Henrik Nielsen"

Background: Epoxy resin monomers are strong skin sensitizers that are widely used in industrial sectors. In Denmark, the law stipulates that workers must undergo a course on safe handling of epoxy resins prior to occupational exposure, but the effectiveness of this initiative is largely unknown.

Objectives: To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences.

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Background: Fragrances frequently cause contact allergy, and cosmetic products are the main causes of fragrance contact allergy. As the various products have distinctive forms of application and composition of ingredients, some product groups are potentially more likely to play a part in allergic reactions than others.

Aim: To determine which cosmetic product groups cause fragrance allergy among Danish eczema patients.

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Background: Fragrance mix II (FM II) is a relatively new screening marker for fragrance contact allergy. It was introduced in the patch test baseline series in Denmark in 2005 and contains six different fragrance chemicals commonly present in cosmetic products and which are known allergens.

Aim: To investigate the diagnostic contribution of including FM II in the baseline series by comparing it with other screening markers of fragrance allergy: fragrance mix I (FM I), Myroxylon pereirae and hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC).

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Background: An association between nickel contact allergy and hand eczema has previously been demonstrated. In 1990, Denmark regulated the extent of nickel release in the ear-piercing process as well as nickel release from consumer products.

Objectives: This study aimed to evaluate the effect of the Danish nickel regulation by comparing the prevalence of concomitant nickel allergy and hand eczema observed in two repeated cross-sectional studies performed in the same general population in Copenhagen.

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The use of nickel in certain consumer goods has been regulated in Denmark since 1990. The aim of this study was to reveal the clinical characteristics of nickel-allergic patients seen in seven private dermatology clinics and to identify current sources of nickel that may elicit nickel dermatitis. During 2006 to 2007, 634 patients with dermatitis aged 17-91 years were patch-tested and completed a questionnaire including a question about the occurrence of dermatitis following skin contact with ear-rings or ear-pins, watches, buttons or metal clasps (i.

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Para-phenylenediamine (PPD), a constituent of permanent hair dyes, may cause contact allergy in exposed individuals. It has previously been questioned whether a patch testing with PPD in population-based epidemiological studies is entirely safe. The Glostrup allergy studies patch tested the same cohort twice.

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Background: Contact allergy is a major public health problem in industrialized countries. Hitherto, known risk factors for contact allergy have mainly included increased exposure to allergens. There are no published data on the relation between smoking and contact allergy.

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Background: Seropositivity to food-borne and orofecal microorganisms (hepatitis A virus, Helicobacter pylori, and Toxoplasma gondii ), which are considered to be markers of poor hygiene, has been reported to be associated with a lower prevalence of atopy. In contrast, colonization of the gut with Clostridium difficile, a potential intestinal bacterial pathogen, in early childhood may be associated with a higher prevalence of atopy.

Objective: The objective of this study was to investigate the association between atopy and exposure to 2 groups of food-borne and orofecal microorganisms: (1) markers of a poor hygiene and (2) intestinal bacterial pathogens.

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Hand eczema is a recurrent chronic skin disease related to contact allergy and atopic dermatitis. When possible, efforts should be redoubled to eliminate provoking factors. Our objective was to assess changes in the prevalence of self-reported hand eczema and to evaluate the association between contact allergy and hand eczema among adult Danes before and after nickel exposure regulation in Denmark.

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Background: There is evidence that the prevalence of respiratory allergy has increased in children in many countries. However, this evidence is largely based on questionnaire data, and little is known about similar trends in adults. We investigated whether the prevalence of specific IgE to aeroallergens had increased in an adult general population over an 8-year period.

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Background: The prevalence of acne among adolescents appears to vary geographically. This study was therefore undertaken to describe the prevalence rate of acne among Danish adolescents and to study the possible influence of oral contraceptives (OC) and tobacco smoking on disease prevalence and severity. Both have been suggested to influence acne and are therefore potential confounders in studies of acne prevalence.

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