A retrospective study of 1064-nm Q-switched Nd:YAG laser therapy for acquired bilateral nevus of Ota-like macules

Abstract

Background: The therapeutic efficacy of laser treatments for acquired bilateral nevus of Ota-like macules (ABNOM) varies among studies, and few studies have evaluated the factors affecting therapeutic effects.

Aims: To evaluate the efficacy and safety of 1064-nm Q-switched Nd:YAG laser (QSNYL) therapy for ABNOM and to identify the factors influencing the outcome.

Methods: A total of 110 patients with ABNOM were retrospectively evaluated and received two-to-nine treatment sessions. The effects of different factors on the therapeutic effect were analyzed on the basis of the number of treatments, age at first treatment, skin type, lesion color, affected area, number of lesion sites, and presence of concomitant melasma.

Results: The curative effect was positively correlated with the treatment time and negatively correlated with the increasing age at first treatment (p < 0.05). The curative effect was better in patients with skin type III than those with type IV ( p < 0.05) and in patients with a lesion area of less than 10 cm² than those with a larger affected area (p < 0.05). Additionally, the treatment effect was poorer in patients with concomitant melasma (p < 0.05). The treatment effect was not significantly correlated with the lesion color or number of affected sites (p > 0.05). Eleven patients (10%) developed postinflammatory hyperpigmentation (PIH).

Conclusions: Early and repeated QSNYL therapy achieved satisfactory results for ABNOM. The risk of PIH after laser treatment is highest among patients with older age, darker lesion color, and darker skin color. For patients with ABNOM with concurrent melasma, low-energy laser therapy is recommended to reduce the risk of melasma aggravation.

Keywords: 1064-nm Q-switched Nd:YAG laser; acquired bilateral nevus of Ota-like macules; melasma; postinflammatory hyperpigmentation; related factors.

FIGURE 1

Assessment of the linear relationship between each factor and age using the Mantel–Haenszel χ ² test. (A) Lesion color in various age groups. The lesion color increased with age (χ ² = 32.411, r = 0.545, p < 0.001). (B) Lesion area in various age groups. The lesion area increased with age (χ ² = 8.714, r = 0.283, p = 0.003). (C) Number of lesion sites in various age groups. The number of lesion sites increased with age (χ ² = 26.381, r = 0.492, p < 0.001). (D) Prevalence of concomitant acquired bilateral nevus of Ota‐like macules (ABNOM) and melasma in various age groups. The probability of ABNOM combined with melasma increased with age (χ ² = 22.496, r = 0.454, p < 0.001). p < 0.05 was considered statistically significant. ABNOM: acquired bilateral nevus of Ota‐like macules; r: Pearson correlation coefficient.

FIGURE 2

Assessment of the linear relationship between each factor and the improvement score using the Mantel–Haenszel χ ² test. (A) Lesion improvement scores in the groups with various numbers of treatment sessions. The improvement score increased as the number of treatment sessions increased (χ ² = 43.365, r = 0.631, p < 0.001). (B) Lesion improvement scores in various age groups. The lesion improvement score decreased with age (χ ² = 13.893, r = −0.357, p < 0.001). p < 0.05 was considered statistically significant. r: Pearson correlation coefficient.

FIGURE 3

Photographs of a woman in her 20s with only acquired bilateral nevus of Ota‐like macules. (A) Before treatment. (B) Disappearance of all lesions after the sixth treatment session.

FIGURE 4

Photographs of a woman in her 20s with only acquired bilateral nevus of Ota‐like macules. (A) Before treatment. (B) Disappearance of all lesions after the fifth treatment session.

FIGURE 5

Photographs of a woman in her 30s with acquired bilateral nevus of Ota‐like macules and slight melasma. (A) Before treatment. (B) After the first laser treatment. (C) After the second laser treatment. (D) After the third laser treatment. In the course of three treatments, melasma showed a gradual deterioration trend.

FIGURE 6

Photographs of a 5‐year‐old girl with acquired bilateral nevus of Ota‐like macules. (A) Before treatment. (B) Good clearance of the lesions after the sixth treatment session.