The expression pattern of N-acetyltransferase 1 in healthy human skin.

BACKGROUND: N-acetyltransferase 1 (NAT1) is an enzyme expressed among others in keratinocytes in human skin. NAT1 is important in the biotransformation of aromatic amines, an important example being p-phenylenediamine (PPD), a hair dye molecule. Unoxidized PPD penetrates the skin and is N-acetylated by NAT1. OBJECTIVES: To investigate in detail the expression pattern of NAT1 in human skin. MATERIALS AND METHODS: Cryosections obtained from healthy human skin were stained for NAT1 and expression patterns were observed. NAT1 double stainings were performed with antibodies against different cellular organelles to determine expression patterns. RESULT: A speckled, granular expression of NAT1 was seen predominantly in the stratum basale. NAT1 was expressed in a cytoplasmic pattern, perinuclear, and in the nucleus. No co-localisation was seen with the selected cellular organelles. Local differences in NAT1 expression patterns were observed between donors and between different biopsies obtained from the same donor. CONCLUSIONS: NAT1 is expressed predominantly in the stratum basale and can be found in the cytoplasm, nucleus, and perinuclear in human skin. Further studies should be performed to investigate expression of NAT1 in a larger sample size.

Skin exposure to scented products used in daily life and fragrance contact allergy in the European general population - The EDEN Fragrance Study.

BACKGROUND: Fragrances are widely used in scented products used in daily life with the potential to induce skin sensitization. OBJECTIVE: To evaluate exposure to scented products and to explore associations between exposure and fragrance contact allergy. METHODS: A cross-sectional study on individuals from 18 to 74 years of age, who were randomly selected from the general population in five European countries. A random sample (N = 3119) was patch tested and interviewed on exposure to scented products. RESULTS: Female participants were strongly associated with exposure to scented products relative to male participants. Participants age 40 years and older showed an inverse association with exposure to scented products. Compared to Sweden, The Netherlands followed by Germany showed the highest overall exposure to scented products. Sensitive skin was associated with exposure to scented products and with fragrance allergy. In univariable regression analysis, exposure to leave-on products and to specific scented product subgroups was significantly associated with fragrance allergy. CONCLUSION: Exposure to scented products depends primarily on sex and age. Female sex and sensitive skin are relevant indicators for developing fragrance allergy. Because aggregate exposure, especially to scented leave-on products, may enhance the prevalence of contact allergy to fragrances, further investigations into exposure amounts and frequencies is warranted.

Allergic contact dermatitis caused by 1,6-hexanediol diacrylate in a hospital wristband.

BACKGROUND: 1,6-Hexanediol diacrylate (1,6-HDDA) is a multifunctional acrylate and a potent sensitizer. OBJECTIVES: To report a case of allergic contact dermatitis caused by 1,6-HDDA in a hospital wristband. METHODS: A male patient presented with eczema on his wrist where he had worn a hospital wristband. Patch testing was performed with our extended European baseline series, additional series, and pieces of the hospital wristband. Thin-layer chromatography (TLC) was performed with extracts from the wristband and gas chromatography-mass spectrometry was used for chemical analysis. RESULTS: Positive reactions were found to pieces of the wristband, including adhesive rim (+++), inside (+++), and outside (++); to multiple allergens in the (meth)acrylates series; and to extracts of the wristband in acetone and ethanol. Chemical analysis of the ethanol extract showed presence of lauryl acrylate and 1,6-HDDA. Patch testing with TLC strips and subsequent chemical analysis showed that the substance causing the strongest reaction was 1,6-HDDA, to which the patient had a confirmed positive patch test reaction. CONCLUSION: 1,6-HDDA was identified as the culprit allergen responsible for allergic contact dermatitis caused by the hospital wristband.

New positive patch test reactions on day 7-The additional value of the day 7 patch test reading.

BACKGROUND: Not performing a day (D) 7 patch test reading might result in positive patch test reactions being missed. OBJECTIVES: To investigate the added value of the D7 patch test reading for individual allergens, and to identify patient characteristics and allergen groups associated with new positive D7 reactions. METHODS: Data from patients patch tested between 2008 and 2018 with the extended European baseline series were analysed. Patch test readings were performed on D3 and D7. Positive reactions were categorized into positive on D3 or new positive on D7. RESULTS: A total of 3292 patients were consecutively patch tested with at least 43 allergens of the TRUE Test panels 1 and 2 supplemented with investigator-loaded allergens. In total, 447 (13.6%) patients showed new positive D7 reactions. In univariable regression analysis, age between 18 and 30 years showed a negative association with new positive D7 reactions. Significantly more D7 positive reactions were seen for topicals (odds ratio [OR] 2.60, 95% confidence interval [CI]: 1.92-3.51) and corticosteroids (OR 1.87, 95%CI: 1.09-3.21). No associations were found between sex, atopic dermatitis and occupational dermatitis and a new positive D7 reaction. CONCLUSION: A D7 reading to identify new positive patch test reactions is of added value, especially for topicals and corticosteroids.