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Henry Ford Hospital


Background: Post-inflammatory hyperpigmentation (PIH) is common following resolution of acne. Purpose: The purpose of this study is to determine the treatment efficacy of Topical Hydrolyzed Psoralea Corylifolia extract (HPCE) on acne-induced PIH and TCA-induced PIH using a previously validated model.1Methods: A prospective, single-blinded, non-randomized study was conducted on 20 subjects with acne-induced PIH. Three acne-induced PIH areas on the face and three 35% TCA-induced PIH areas on the buttocks were analyzed. Subjects received topical HPCE [Unigen] and vehicle cream with instructions on twice daily application on two separate facial and gluteal lesions for 28 days; the third lesion served as a control. Clinical photography and Investigator Global Assessment (IGA) scores for hyperpigmentation were performed on days 0, 28, 35, 42, and 56 for all sites. Degree of improvement was defined as the change in the IGA score for hyperpigmentation between the first and last day of treatment. Results: For facial acne sites, one-way repeated measures ANOVA for degree of improvement as assessed by IGA analysis demonstrated a greater degree of improvement for product sites when compared to vehicle (1.9 times) and control (1.5 times); however, statistical significance was not reached. For TCA-induced PIH sites, there was a statistically significant degree of improvement for product treated sites compared to vehicle (9 times) and control (9 times). For both acne and TCA-induced PIH sites, Pearson correlation coefficient between time and IGA score for hyperpigmentation showed a strong and statistically significant (p<0.05) correlation for the product site. Such significant correlation was not observed for vehicle and control sites. Conclusion: Statistically significant improvement in TCA-induced PIH sites and some improvements in acne sites were observed for HPCE sites compared to control and vehicle sites. A strong statistically significant correlation between time and each parameter for HPCE treated sites implies that continued treatment and a longer follow-up period could have resulted in clinically significant improvement in HPCE treated acne sites. The TCA model resulted in three identical PIH lesions to be followed over time, whereas there were differences in acne sites at baseline. The findings indicate the relevance of using TCA as a model and suggest that topical HPCE may decrease the impact of PIH, a significant quality of life issue for patients.

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The Efficacy of Topical Hydrolyzed Psoralea corylifolia Extract in Treating Postinflammatory Hyperpigmentation