# High Resolution Ultrasound for the Assessment of Melasma: Experience With 1064 nm Q-Switched Nd:YAG Laser

## TL;DR

This study explores using high-resolution ultrasound to monitor skin changes in melasma patients before and after laser treatment, showing potential for personalized dermatological care.

## Contribution

The study introduces high-resolution dermatologic ultrasound as a novel method to assess melasma and its response to laser therapy.

## Key findings

- Baseline ultrasound showed subepidermal low-echogenic bands and increased vascularization in melasma patients.
- Laser therapy reduced subepidermal bands and improved skin echogenicity and capillarity.
- HRDU effectively documented subclinical inflammation and solar elastosis changes.

## Abstract

Melasma is a challenging chronic pigmentary disorder that holds considerable significance for both patients and dermatologists. Monitoring therapeutic outcomes is essential for optimizing treatment strategies. This study aimed to apply high-resolution dermatologic ultrasound (HRDU) to evaluate skin changes in melasma patients and document the effects observed following the application of collimated and fractional forms of 1064 nm Q-switched Nd:YAG (QSNY) laser therapy.

In a prospective case series conducted from December 2024 to February 2025 at a private dermatology clinic, three patients with melasma who were indicated for QSNY laser treatment were enrolled. Each patient underwent three high-resolution dermatologic ultrasound examinations: the first before initiating QSNY laser therapy, the second 24-48 hours after the initial session, and the third three weeks following the third session. Demographic data of the sample, Melasma Severity Index (MSI) score, ultrasound grayscale, and color Doppler features were recorded and analyzed.

At baseline, all patients demonstrated a subepidermal low-echogenic band (SLEB), follicular dilation, and increased vascularization in the forehead and/or cheek regions. Following the laser sessions, we observed a decrease in the SLEB, an improvement in echogenicity, and an increase in dermal capillarity. These findings provide innovative documentation of skin changes in melasma, including subclinical inflammation and solar elastosis, and highlight the potential of low fluence, fractionated QSNY laser to reduce them. HRDU emerges as a valuable tool to confirm and monitor these therapeutic benefits, supporting its role in personalized treatment strategies for melasma.