Efficacy of 532-nm Nd: YAG Fractional Picosecond Laser with 9 mm High Coverage Handpiece Micro Lens Array in the Treatment of Facial Partial Unilateral Lentiginosis: A Case Report.

Facial partial unilateral lentiginosis (PUL) is an infrequent skin pigmentation disorder characterized by multiple lentigines. Despite the availability of various treatment modalities, there is no standard treatment for PUL. This study reports a successful treatment of facial PUL in a female patient using a novel 532-nm Nd:YAG fractional picosecond laser (FPL). The patient underwent four treatment sessions at four-week intervals. The treatments were administered using a 9 mm high coverage handpiece micro lens array (MLA), with a fluence of 0.2-0.4 J/cm, a frequency of 2 Hz for 2-3 passes, and approximately 10% overlap. The treatment was well-tolerated by the patient, with significant improvement in pigmentation and no significant side effects observed. The outcomes confirmed the efficacy of the 532-nm Nd:YAG FPL in treating facial PUL. The 532-nm Nd:YAG FPL appears to be an effective and well-tolerated treatment for facial PUL, offering significant improvement in pigmentation without notable side effects.