Evaluating the Risk Factors of Post Inflammatory Hyperpigmentation Complications with Nd-YAG Laser Toning Using LASSO-Based Algorithm

Chao-Hong Liu,Yu-Jie Huang,Tsair-Fwu Lee,Chih-Hsueh Lin,Stephen Wan Leung,Jia-Ming Wu,Chin-Shiuh Shieh,Chin-Dar Tseng,Pei-Ju Chao,Shyh-An Yeh,Tai-Lin Huang,Hsiao-Fei Lee

doi:10.3390/app10062049

Abstract

The neodymium-doped yttrium aluminum garnet (Nd-YAG) laser is used for removal of pigmented skin patches and rejuvenation of skin. However, complications such as hyperpigmentation, hypopigmentation, and petechiae can occur after frequent treatments. Therefore, identifying the risk factors for such complications is important. The development of a multivariable logistic regression model with least absolute shrinkage and selection operator (LASSO) is needed to provide valid predictions about the incidence of post inflammatory hyperpigmentation complication probability (PIHCP) among patients treated with Nd-YAG laser toning. A total of 125 female patients undergoing laser toning therapy between January 2014 and January 2016 were examined for post-inflammatory hyperpigmentation (PIH) complications. Factor analysis was performed using 15 potential predictive risk factors of PIH determined by a physician. The LASSO algorithm with cross-validation was used to select the optimal number of predictive risk factors from the potential factors for a multivariate logistic regression PIH complication model. The optimal number of predictive risk factors for the model was five: immediate endpoints of laser (IEL), α-hydroxy acid (AHA) peels, Fitzpatrick skin phototype (FSPT), acne, and melasma. The area under the receiver operating characteristic curve (AUC) was 0.79 (95% CI, 0.70–0.88) in the optimal model. The overall performance of the LASSO-based PIHCP model was satisfactory based on the AUC, Omnibus, Nagelkerke R2, and Hosmer–Lemeshow tests. This predictive risk factor model is useful to further optimize laser toning treatment related to PIH. The LASSO-based PIHCP model could be useful for decision-making.

Highlights

Laser toning with a low-fluence 1064 nm Q-switched neodymium-doped yttrium aluminum garnet (Nd-YAG) laser can be used for removal of pigmented skin patches and rejuvenation of skin [1,2]
We found that post-inflammatory hyperpigmentation (PIH) can be predicted in laser toning patients using the least absolute shrinkage and selection operator (LASSO)-based post inflammatory hyperpigmentation complication probability (PIHCP) model with cross-validation
The predictive risk factor model described will be useful to further optimize laser toning treatment with respect to PIH. This LASSO-based PIHCP model indicates the most important risk factors for PIH (IEL, α-hydroxy acid (AHA) peel, Fitzpatrick skin phototype (FSPT), acne, and melasma), which will aid in decision making regarding treatment, helping to reduce PIH as much as possible and in the optimization of current laser toning treatment protocols

Summary

Introduction

Laser toning with a low-fluence 1064 nm Q-switched neodymium-doped yttrium aluminum garnet (Nd-YAG) laser can be used for removal of pigmented skin patches and rejuvenation of skin [1,2]. Laser toning involves multiple passes of a low-fluence Q-switched Nd-YAG laser used for treatment of facial hyperpigmentation and skin rejuvenation. The side effects of rebound post-inflammatory hyperpigmentation (PIH) are common after laser toning treatment. PIH is an acquired hyperpigmentation at the sites of previous skin inflammation, injuries, irritants, or allergic dermatitis, and cosmetic procedures such as chemical peeling and laser treatment. Song et al reported that the increase in epidermal pigmentation after laser irradiation is related to the increased expression of certain inflammatory cytokines, suggesting that they may be the cause of PIH induction [5].

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Discussion

Conclusion