title: Allergic reactions in red tattoos: Raman spectroscopy for 'fingerprint' detection of chemical risk spectra in tattooed skin and culprit tattoo inks.
abstract: OBJECTIVE
  The aim of this study was to assess the feasibility of Raman spectroscopy as a screening technique for chemical characterisation of tattoo pigments in pathologic reacting tattoos and tattoo ink stock products to depict unsafe pigments and metabolites of pigments.
  
  
  METHODS
  Twelve dermatome shave biopsies from allergic reactions in red tattoos were analysed with Raman spectroscopy (A 785-nm 300 mW diode laser). These were referenced to samples of 10 different standard tattoo ink stock products, three of these identified as the culprit inks used by the tattooist and thus by history the source of the allergy. Three primary aromatic amine (PAA) laboratory standards (aniline, o-anisidine and 3,3'-dichlorobenzidine) were also studied.
  
  
  RESULTS
  Application of Raman spectroscopy to the shave biopsies was technically feasible. In addition, all ten inks and the three PAA standards could be discriminated. 10/12 shave biopsies provided clear fingerprint Raman signals which differed significantly from background skin, and Raman spectra from 8/12 biopsies perfectly matched spectra from the three culprit ink products. The spectrum of one red ink (a low cost product named 'Tattoo', claimed to originate from Taiwan, no other info on label) was identified in 5/12 biopsies. Strong indications of the inks 'Bright Red' and 'Crimson Red' were seen in three biopsies. The three PAA's could not be unambiguously identified.
  
  
  CONCLUSIONS
  This study, although on a small-scale, demonstrated Raman spectroscopy to be feasible for chemical analysis of red pigments in allergic reactions. Raman spectroscopy has a major potential for fingerprint screening of problematic tattoo pigments in situ in skin, ex vivo in skin biopsies and in tattoo ink stock products, thus, to eliminate unsafe ink products from markets.
authors.affiliation: Department of Dermatology, The "Tattoo Clinic", Bispebjerg University Hospital, Copenhagen, Denmark. katrinahuttoncarlsen@hotmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Hutton Carlsen
authors.affiliation: Chemistry and Biotechnology, Danish Technological Institute, Aarhus, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Køcks
authors.affiliation: Centre of Wound Healing, Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Sepehri
authors.affiliation: Department of Dermatology, The "Tattoo Clinic", Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Serup
mesh_terms: D000328:Adult; D003116:Color; D004396:Coloring Agents / Q000009:adverse effects* / Q000032:analysis / Q000737:chemistry*; D003875:Drug Eruptions / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007281:Ink; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000737:chemistry* / Q000187:drug effects* / Q000473:pathology; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013653:Tattooing / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D004396:Coloring Agents
keywords: Raman spectroscopy; ink; pigment; safety; tattoo allergy