title: Change in ultraviolet (UV) transmission following the application of vaseline to non-irradiated and UVB-exposed split skin.
abstract: BACKGROUND
  Topical preparations such as emollients used in combination with phototherapy can interfere with such treatment.
  
  
  OBJECTIVE
  This study was performed to investigate the impact of vaseline on the ultraviolet (UV) transmission of non-irradiated split skin and on split skin previously exposed to UVB radiation.
  
  
  METHODS
  Split-skin specimens were obtained from 20 patients. In each case, one sample was taken from an area of non-irradiated skin, while the second was taken from an area that had been previously exposed to UVB. The transmission was spectrophotometrically measured with split skin placed in specially designed quartz glass cuvettes before and after the application of two different amounts of vaseline (2.5 and 17.5 mg cm-2).
  
  
  RESULTS
  Application of vaseline to skin previously exposed to UVB caused significant (P < 0.0001) changes in UV transmission in certain wavelength ranges. In the UVA range, a greater increase in transmission was achieved with 2.5 mg cm-2 vaseline, whereas in the UVB range, a greater increase was achieved with 17.5 mg cm-2 vaseline. The thicker the layer of vaseline applied, the lower was the difference in transmission between non-irradiated split skin and UVB-exposed split skin.
  
  
  CONCLUSIONS
  Application of the correct amount of vaseline can enhance transmission in either the UVA or UVB range, and would enable dose reduction during a course of phototherapy.
authors.affiliation: Department of Dermatology, Clinical and Experimental Photodermatology, Ruhr University Bochum, Gudrunstrasse 56, D-44791 Bochum, Germany. K.Hoffmann@derma.de
authors.forename: K
authors.initials: K
authors.lastname: Hoffmann
authors.forename: K
authors.initials: K
authors.lastname: Kaspar
authors.forename: T
authors.initials: T
authors.lastname: Gambichler
authors.forename: P
authors.initials: P
authors.lastname: Altmeyer
mesh_terms: D000328:Adult; D004305:Dose-Response Relationship, Drug; D004643:Emollients / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010577:Petrolatum / Q000008:administration & dosage*; D011829:Radiation Dosage; D012867:Skin / Q000187:drug effects* / Q000528:radiation effects*; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D004643:Emollients; D010577:Petrolatum