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

ABSTRACT Background The efficacy of laser treatment for facial café au lait macules (CALMs) is random. Aim To compare the response of different characteristics of CALMs skin lesions to laser treatment. Patients/Methods 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. Results 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). Conclusions 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.