Lifestyle and nickel allergy in a Swedish adolescent population: effects of piercing, tattooing and orthodontic appliances.

The aim of this study was to estimate the prevalence of life-style practices in adolescents and their association with nickel allergy. Upper secondary school pupils (n = 4,376; 15-23 years) were patch-tested for nickel aller-gy, follow-ing completion of a questionnaire (answered by 6,095). Almost 86% girls and 21% of boys reported piercing. More girls (6%) than boys (3%) had a tattoo. Twenty-six percent of the girls and 18% of the boys were regular smokers. Vegetarian/vegan diets were reported by 20% of girls and by 6% of boys. Piercing, female gender, and vocational programme increased the risk of nickel allergy, whereas orthodontic appliance treat-ment prior to piercing reduced the risk of nickel allergy. Pupils in vocational programmes had the highest prevalence of nickel allergy. Lifestyle behaviours are interconnected and cluster in subgroups of adolescents. Female sex, piercing and choice of educational programme are prominent lifestyle markers. A trend shift is observed, where more girls than boys report tattooing.

Nickel allergy--prevalence in a population of Swedish youths from patch test and questionnaire data.

BACKGROUND: The prevalence of body piercing and orthodontic treatment has increased during recent decades. Such changes in lifestyle may influence the occurrence of nickel allergy. OBJECTIVES: The aim of this study was to describe the prevalence of nickel allergy in a Swedish youth population. METHODS: In a cross-sectional survey, 6095 adolescents answered a questionnaire on their lifestyle and medical history, and 4439 consented to patch testing for contact allergy. Patch test results were adjusted for dropouts by a missing value analysis. RESULTS: The prevalence of self-reported dermatitis from contact with metal items was 14.8%. Patch testing showed nickel sensitization in 9.9% of the subjects, and in significantly more girls than boys, 13.3% versus 2.5%, respectively. Taking the dropout into account, the estimated true prevalence of nickel sensitivity evaluated by test reading at D4 is 11.8% in girls and 1.6% in boys. CONCLUSIONS: The prevalence of nickel sensitization was higher for girls and slightly lower for boys compared with previous Swedish data. Self-reported information on metal dermatitis as an estimate of nickel allergy has low validity. When possible, missing value analysis should be performed to account for dropouts.

Nickel allergy and hand eczema--a 20-year follow up.

The aim of this study was to investigate the occurrence of hand eczema after 20 years in women patch tested to nickel during childhood. In 1982-1983, 960 schoolgirls were patch tested for nickel allergy; its prevalence was found to be 9%. 20 years later, the same individuals received a questionnaire regarding hand eczema and factors of importance for the development of hand eczema. 735 of 908 women (80.9%) answered the questionnaire. In total, 17.6% of respondents reported hand eczema after the age of 15 years, and the 1-year prevalence was 12.8%. There was no statistically significant difference in the occurrence of hand eczema between the groups who had previously tested positive and negative for nickel allergy. 38.3% of the respondents considered themselves to be nickel sensitive at the time they answered the questionnaire; in this group, the reported prevalence of hand eczema after age 15 was 22.5%. 31.4% of those with a history of atopic dermatitis reported hand eczema after age 15, compared with 10.6% of those without (P < 0.001). In conclusion, contact allergy to nickel in childhood did not seem to increase the prevalence of hand eczema later in life.