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Updated: Mar 28, 2026
Quantification of Hypopigmentation Activity In Vitro
Published on: March 6, 2019
An in vivo model for postinflammatory hyperpigmentation: an analysis of histological, spectroscopic, colorimetric and
P Isedeh1, I Kohli1, M Al-Jamal1
1Multicultural Dermatology Center, Department of Dermatology, Henry Ford Hospital, New Center One, 3031 West Grand Blvd, Suite 800, Detroit, MI, 48202, U.S.A.
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.
Objectives:
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.
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