title: Hand eczema in nickel-sensitive female twins. Genetic predisposition and environmental factors.
abstract: The Danish Twin Register represents a population-based twin sample where the twins enter the Register independently of disease. All female twins born between 1906-30 and available in the Register in January 1978 were sent a questionnaire concerning possible nickel sensitivity. Among 746 pairs living in the eastern part of Denmark, 129 twins from 115 pairs had a possible nickel allergy. Through a subsequent personal visit and, in most cases, patch testing, 34 monozygotic probands from 30 pairs and 45 dizygotic probands from 41 pairs were considered to have a verified nickel sensitivity and fulfilled the restriction criteria for the present study. The prevalence of present or previous hand eczema in both the monozygotic and the dizygotic probands was 41% (95% confidence limits: 30-52%). In 15 of the 32 with hand eczema, this was in the form of a relapsing pompholyx. Analysis of the monozygotic pairs showed that the risk of developing hand eczema in the co-twins seemed independent of whether the proband had nickel allergy and hand eczema or nickel allergy alone. Furthermore, it was found that the number of affected co-twins was comparable with the background population. Thus the association between nickel allergy and hand eczema is probably not due to a common genetic predisposition. Environmental factors seem decisive.
mesh_terms: D000368:Aged; D003876:Dermatitis, Atopic / Q000139:chemically induced / Q000235:genetics*; D003877:Dermatitis, Contact / Q000209:etiology; D004200:Diseases in Twins; D005260:Female; D006229:Hand Dermatoses / Q000139:chemically induced / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D009532:Nickel / Q000009:adverse effects*; D010328:Patch Tests; D011247:Pregnancy; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
chemical_list: D009532:Nickel