Prospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 26, 2021; 9(18): 4681-4689
Published online Jun 26, 2021. doi: 10.12998/wjcc.v9.i18.4681
Clinical outcomes and 5-year follow-up results of keratosis pilaris treated by a high concentration of glycolic acid
Yan Tian, Xiao-Xin Li, Jiao-Jiao Zhang, Qing Yun, Si Zhang, Jia-Yi Yu, Xue-Jiao Feng, Ai-Ting Xia, Yang Kang, Feng Huang, Fang Wan
Yan Tian, Xiao-Xin Li, Jiao-Jiao Zhang, Qing Yun, Si Zhang, Jia-Yi Yu, Xue-Jiao Feng, Ai-Ting Xia, Feng Huang, Fang Wan, Department of Dermatology, Air Force Characteristic Medical Center, Beijing 100142, China
Yang Kang, Center of Medical and Health, Unit 71901 of PLA, Liaocheng 252000, Shandong Province, China
Author contributions: Tian Y and Li XX contributed equally to this work, and are co-first authors; Tian Y contributed to the conception of the study; Tian Y and Li XX contributed significantly to analysis and manuscript preparation; Li XX performed the data analyses and wrote the manuscript; Zhang JJ, Yu JY and Feng XJ are responsible for the treatment process; Yun Q, Zhang S, Xia AT, Kang Y, Huang F, and Wan F helped perform the analysis with constructive discussions.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of the Air Force Characteristic Medical Center (Approval No. 2020-160-PJ01).
Clinical trial registration statement: This study was not registered.
Informed consent statement: All study participants, or their legal guardian, provided written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
Data sharing statement: No additional data is available.
CONSORT 2010 statement: The manuscript was revised according to the CONSORT 2010 statement.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yan Tian, MD, PhD, Chief Doctor, Professor, Department of Dermatology, Air Force Characteristic Medical Center, No. 30 Fucheng Road, Haidian District, Beijing 100142, China. tianyan311@126.com
Received: January 26, 2021
Peer-review started: January 26, 2021
First decision: February 28, 2021
Revised: March 11, 2021
Accepted: April 22, 2021
Article in press: April 22, 2021
Published online: June 26, 2021
Processing time: 135 Days and 23.3 Hours
Abstract
BACKGROUND

Keratosis pilaris is a hereditary abnormal keratosis of the hair follicle orifice. Gray-brown keratotic plugs in the pores and dark red keratotic papules at the openings of hair follicles can be seen, which contain coiled hair and are often accompanied by perifollicular erythema and pigmentation. Glycolic acid can correct the abnormalities of hair follicular duct keratosis and eliminate excessive accumulation of keratinocytes. It also promotes skin metabolism and accelerates the melanin metabolism. The therapeutic effect is related to the glycolic acid concentration.

AIM

To evaluate the efficacy and safety of a high concentration of glycolic acid in the treatment of keratosis pilaris, and to observe the outcomes at 5-year of follow-up.

METHODS

Twenty-five participants were recruited and areas with typical keratosis pilaris were selected as testing sites. High concentrations of glycolic acid (50% or 70%) were applied to a circular area (d = 8 cm, S = 50 cm2) and repeated four times, on days 0, 20, 40 and 60. Before each treatment and 20 d after the last treatment, on days 0, 20, 40, 60, and 80 and at a 5-year follow-up, The number of follicular keratotic papules were counted and the extent of perifollicular erythema and pigmentation was determined. At the same time, the participants provided subjective evaluations of treatment efficacy and safety.

RESULTS

Treatment effectiveness was indicated by the percentage of keratotic papules in the test site, on days 20, 40, 60 and 80, which were 8%, 12%, 36%, and 60%, respectively. Compared with day 0, each difference was significant (P < 0.05). Compared with day 0, differences in melanin content (M) in the skin and skin lightness (L) on days 40, 60 and 80, the were statistically significant (P < 0.05); skin hemoglobin content (E) on days 60 and 80 was statistically different as compared with before treatment (P < 0.05). There were no significant differences in the number of keratotic papules, M, L, and E in 9 participants at the 5-year follow-up compared with before treatment (P > 0.05%).

CONCLUSION

A high concentration of glycolic acid significantly improved skin roughness as well as follicular hyperpigmentation of patients with keratosis pilaris. The treatment was relatively safe, but there was no significant difference at the 5-year follow-up compared to before treatment.

Keywords: Keratosis pilaris; Glycolic acid; Keratotic papules; Follicular erythema; Melanin pigmentation

Core Tip: A high concentration of glycolic acid (50%, 70%) was applied to 25 subjects suffering from keratosis pilaris. The treatment was repeated every 20 d for a total of four times, 20 d after each treatment, perifollicular erythema, papules, and pigmentation were evaluated by spectrophotometry, counting and an Mexameter®. We found a high concentration of glycolic acid had a therapeutic effect on perifollicular erythema, papules and pigmentation, and as the number of treatments and the concentration of glycolic acid increased, the therapeutic effect improved further, but a long-term effect was not observed.