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.


OBJECTIVE
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.
Fors
Ronny
R
Department of Odontology, Orthodontics, Umeå University, SE 901 87 Umeå, Sweden. ronny.fors@odont.umu.se
Persson
Maurits
M
Bergström
Erik
E
Stenlund
Hans
H
Stymne
Birgitta
B
Stenberg
Berndt
B
D000293:Adolescent; D000328:Adult; D003035:Cobalt / Q000009:adverse effects; D003430:Cross-Sectional Studies; D003625:Data Collection; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D004485:Eczema / Q000453:epidemiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009532:Nickel / Q000009:adverse effects*; D010328:Patch Tests; D010352:Patient Dropouts; D015995:Prevalence; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology
D003035:Cobalt; D009532:Nickel