Efficacy and Safety of 755-nm Picosecond Alexandrite Laser for Acquired Bilateral Naevus of Ota-Like Macules (Hori Naevus): A Systematic Review and Meta-Analysis.

Acquired bilateral naevus of Ota-like macules (ABNOM), also known as Hori's naevus, is a common dermal melanocytosis causing facial hyperpigmentation. While the 755-nm Q-switched alexandrite lasers (QSAL) are traditionally used, they are limited by moderate clearance and substantial risk of post-inflammatory hyperpigmentation (PIH). This systematic review and meta-analysis evaluate the efficacy and safety of the 755-nm picosecond alexandrite laser (PSAL) for ABNOM. Embase via Ovid, MEDLINE, PubMed, Scopus, Cochrane, Web of Science and CiNAHL were searched from inception to April 14, 2026, according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The review was prospectively registered on PROSPERO (CRD420261379083). Studies reporting efficacy or safety outcomes following PSAL treatment for ABNOM were included. Statistical analyses were performed using a random-effects model. Six studies comprising 318 patients (94.6% female, predominantly Fitzpatrick skin types III-IV) were included. After excluding studies at critical risk of bias from quantitative pooling, the pooled first-session near-complete (> 90%-95%) clearance rate was 8.8% (95% CI 5.9%-12.7%; I2 = 0%). Clearance rates improved progressively with additional sessions. The overall pooled PIH rate was 21.1% (95% CI 17.1%-26.1%; I2 = 0%), with all cases being transient. Hypopigmentation (0.6%) and scarring (0%) were rare. Numerically lower PIH rates were observed in the paediatric cohort (16.3%) compared with adults (22.2%). PSAL provides an effective treatment for ABNOM with progressive pigment clearance over multiple sessions and a favourable safety profile. Multiple sessions are typically required for optimal results. Further high-quality RCTs with standardised protocols and long-term follow-up are warranted.