ABNOMhttps://en.wikipedia.org/wiki/Hori's_nevus
ABNOM is a cutaneous condition characterized by multiple brown–gray to brown–blue macules, primarily in the malar region of the face. It can also occur simultaneously with other pigmentary skin diseases such as melasma, freckles, multiple lentigines and Ota's nevus. Only minimal change is observed in this dark spots, whereas the melasma have become darker and lighter as the continuous pigment production and decrease.

○ Treatment
Whitening agents rarely help. Unlike melasma, ABNOM can be improved with laser treatment and left to be removed without recurrence. Laser treatment can be performed 10 to 20 times to treat ABNOM.
#QS1064 laser
      References High-fluence 1064nm Q-switched Nd:YAG laser treatment for ectopic Mongolian spot 37781886
      The Q-switched Nd:YAG laser is known to effectively treat nevus of Ota and similar conditions. We conducted a study to see how well a high-fluence 1064 nm Q-switched Nd:YAG laser worked on Mongolian spots in unusual areas, without causing the skin to lighten. We studied 61 patients with these spots, examining a total of 70 lesions. Half of lesions were treated with the laser, while others were left untreated for comparison. We evaluated the results using a scale and a device called a Mexameter® to measure melanin levels. Patients were followed up for an average of 14 months in the treatment group and 18 months in the observation group. At the end of the study, we found significant differences in the scale scores and melanin levels between the treated and untreated groups, with the laser-treated group showing better outcomes. The high-fluence Q-switched Nd:YAG laser, without causing skin lightening, proved effective and safe for treating these unusual Mongolian spots.
       A retrospective study of 1064-nm Q-switched Nd:YAG laser therapy for acquired bilateral nevus of Ota-like macules 36973977 
      NIH
      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. A total of 110 patients with ABNOM were retrospectively evaluated and received two-to-nine treatment sessions. 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). 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.