# Characteristics of Skin Lesions Determine the Therapeutic Response of Facial Café Au Lait Macules Laser Therapy

## TL;DR

This study finds that the characteristics of facial café au lait macules, such as their distribution and border shape, influence how well they respond to laser therapy.

## Contribution

The study identifies lesion distribution and border shape as predictors of laser therapy efficacy for café au lait macules.

## Key findings

- Segmental and irregular border CALMs showed better responses to laser therapy.
- The overall effective treatment rate was 62.07%.
- Lesion characteristics significantly predicted therapeutic outcomes.

## Abstract

The efficacy of laser treatment for facial café au lait macules (CALMs) is random.

To compare the response of different characteristics of CALMs skin lesions to laser treatment.

In this single‐center retrospective case series, patients with café au lait macules who received laser treatment between 2015 and 2022 at our clinic were reviewed. A total of 319 consecutive patients were eligible and were treated with either a 755‐nm‐alexandrite picosecond laser or a quality‐switched 755‐nm‐alexandrite laser. Observers were blinded to the final patient groups. Efficacy was graded according to four levels of treatment response: poor (Grade 1, 0%–25% improvement), fair (Grade 2, 26%–50% improvement), good (Grade 3, 51%–75% improvement), and excellent (Grade 4, 76%–100% improvement). Treatment effects evaluated as Grades 2–4 were considered effective.

Of the 319 patients, excellent and good responses were observed in 80 (25.08%) and 66 (20.69%) cases, respectively. Fifty‐two patients (16.30%) displayed an outcome of Grade 2 (26%–50% improvement), whereas 121 (37.93%) cases showed an outcome of Grade 1 (0%–25% improvement). The overall treatment effective rate (Grades 2–4) was 62.07%. Binary logistic regression analysis showed a significant association of therapeutic efficacy with lesion distribution (segmental vs. non‐segmental CALMs) and lesion border (irregular vs. regular) (p < 0.05 for both).

Segmental and irregular border CALMs tended to respond well to laser therapy. Clinicians can leverage these characteristics to predict efficacy and manage patient expectations more effectively.