title: An in vivo model for postinflammatory hyperpigmentation: an analysis of histological, spectroscopic, colorimetric and clinical traits.
abstract: BACKGROUND
  Acne vulgaris is a common condition that occurs in all skin types. Postinflammatory hyperpigmentation (PIH) is often associated with acne in patients of darker skin types, making it a common complaint in dermatology offices. Despite this, there is limited understanding of and effective treatment options for PIH.
  
  
  OBJECTIVE
  The study objective was to validate an in vivo model for PIH and to compare the clinical, histological and spectroscopic characteristics of artificially induced PIH and acne-induced PIH.
  
  
  METHODS
  A nonblinded, nonrandomized pilot study was performed. Thirty subjects served as their own control in which four sites treated with 35% trichloroacetic acid (TCA) solution and four truncal acne pustules were followed for 8 weeks and were evaluated clinically and histologically, and by colorimetry and spectroscopy.
  
  
  RESULTS
  The initial phases of inflammation between TCA- and acne-induced PIH differ. However, clinical evaluations were similar on and after day 14. Acne- and TCA-induced lesions were clinically, histologically and spectroscopically indistinguishable at day 28.
  
  
  CONCLUSIONS
  Clinical, spectroscopic and histological similarities of acne-induced and TCA-induced PIH at day 28 suggest that TCA-induced PIH can be a reproducible model for the study of acne-induced PIH.
authors.affiliation: Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: P
authors.initials: P
authors.lastname: Isedeh
authors.affiliation: Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: I
authors.initials: I
authors.lastname: Kohli
authors.affiliation: Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: M
authors.initials: M
authors.lastname: Al-Jamal
authors.affiliation: Department of Dermatology, University of California, Davis, Sacramento, CA, U.S.A.
authors.forename: O N
authors.initials: ON
authors.lastname: Agbai
authors.affiliation: Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: M
authors.initials: M
authors.lastname: Chaffins
authors.affiliation: Department of Radiation Oncology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: S
authors.initials: S
authors.lastname: Devpura
authors.affiliation: Department of Public Health Sciences, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: M
authors.initials: M
authors.lastname: Mahan
authors.affiliation: Estée Lauder Companies, Melville, NY, U.S.A.
authors.forename: G
authors.initials: G
authors.lastname: Vanderover
authors.affiliation: Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: H W
authors.initials: HW
authors.lastname: Lim
authors.affiliation: Estée Lauder Companies, Melville, NY, U.S.A.
authors.forename: M S
authors.initials: MS
authors.lastname: Matsui
authors.affiliation: Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
authors.forename: I H
authors.initials: IH
authors.lastname: Hamzavi
mesh_terms: D000152:Acne Vulgaris / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002424:Caustics / Q000633:toxicity; D003124:Colorimetry; D004890:Erythema / Q000139:chemically induced / Q000473:pathology; D006801:Humans; D017495:Hyperpigmentation / Q000139:chemically induced / Q000473:pathology*; D008875:Middle Aged; D008954:Models, Biological; D010865:Pilot Projects; D013057:Spectrum Analysis; D014238:Trichloroacetic Acid / Q000633:toxicity; D055815:Young Adult
chemical_list: D002424:Caustics; D014238:Trichloroacetic Acid