title: UV-induced skin changes due to regular use of commercial sunbeds.
abstract: OBJECTIVE
  Increased pigmentation and thickening of the epidermis are the most important photoprotective skin reactions induced by ultraviolet (UV) radiation. The present study was designed to find out what changes are induced by regular use of commercial sunbeds twice weekly over a period of 6 weeks.
  
  
  METHODS
  The parameters analysed were skin pigmentation measured by chromametry, minimal erythema dose (MED) as a parameter of light sensitivity, epidermal thickening as determined by histology, induction of keratinocyte apoptosis as determined by TUNEL staining and antioxidant metabolism as measured by changes of cis- and trans-urocanic acid (UCA) content of the skin.
  
  
  RESULTS
  As expected, chromametry confirmed the clinically obvious increased skin pigmentation. However, no increase in MED was observed. In addition, neither epidermal thickening nor sunburn cells were seen. Significant detectable changes in proportion of the UCA isomer content of the UV-exposed skin were seen. The total UCA and cis-UCA content increased significantly between nearly all points of measurement. The amount of trans-UCA first decreased, then increased significantly between the different time points.
  
  
  CONCLUSIONS
  Our data indicate that sunbed-induced tanning is non-protective, which has to be addressed for persons looking for this effect before planning a stay in a sunny climate. However, sunbed-induced tanning may influence immunological reactions.
authors.affiliation: Department of Dermatology and Allergology Biederstein, Technical University Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Ruegemer
authors.forename: B
authors.initials: B
authors.lastname: Schuetz
authors.forename: K
authors.initials: K
authors.lastname: Hermann
authors.forename: R
authors.initials: R
authors.lastname: Hein
authors.forename: J
authors.initials: J
authors.lastname: Ring
authors.forename: D
authors.initials: D
authors.lastname: Abeck
mesh_terms: D000293:Adolescent; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D012880:Skin Pigmentation / Q000528:radiation effects*; D018709:Statistics, Nonparametric; D014466:Ultraviolet Rays / Q000009:adverse effects; D014560:Urocanic Acid / Q000378:metabolism
chemical_list: D014560:Urocanic Acid