Q-switched neodymium-yttrium aluminum-garnet (Q-switched Nd:YAG) laser has been reported as an effective treatment for nevus of Ota and acquired bilateral nevus of Ota-like macules (ABNOM). Data on ectopic Mongolian spots have rarely been reported.The present study was performed to investigate the treatment efficacy of a high-fluence 1064 nm Q-switched Nd:YAG laser without tissue whitening in ectopic Mongolian spots.We included 61 patients with ectopic Mongolian spots, and 70 lesions were examined. Thirty-three lesions were treated with a high-fluence 1064 nm Q-switched Nd:YAG laser, and 38 lesions were observed without treatment. The results were assessed using a 5-quantile grading scale and melanin index using a Mexameter®.Mean follow-up duration was 14.1 ± 6.8 months for the treatment group and 17.8 ± 10.0 months for the observation group. Mean 5-quintile grading scale at final follow-up was statistically different (p < 0.001) between the two groups (treatment: 2.85 ± 1.00, observation: 0.49 ± 0.73). There was a significant difference (p < 0.001) in the Δ melanin index (initial melanin index - final melanin index) between the observation (7.1 ± 62.7) and treatment (156.7 ± 78.4) groups.High-fluence Q-switched Nd:YAG laser without tissue whitening showed good results and was well-tolerated in treating ectopic Mongolian spots.
Keywords: Dermal melanocytosis; Q-switched Nd:YAG laser; ectopic mongolian spot; treatment.