Background:  Keratosis pilaris (KP) is a very common disorder; yet, very few treatment options are available. Objectives: To evaluate the efficacy of long-pulsed 1064-nm Nd:YAG laser for the treatment of KP.

Materials and methods: Eighteen patients with untreated KP on the upper outer arms were enrolled in a randomized clinical trial. One arm was treated with long-pulsed 1064-nm Nd:YAG laser at 30 msec pulse width and fluence of 34 J/cm², while the contralateral arm served as control. Patients received three consecutive treatments at 4-week intervals. Three blinded dermatologists assessed digital photographs using a quartile grading system to separately rate global improvement, erythema and the number of keratotic papules.

Results: Seventeen patients completed the study. There were statistically significant improvements in global assessment, erythema and the number of keratotic papules at 4 weeks after the last treatment (p < 0.05). All patients also stated that their lesions improved and were satisfied with the laser treatment.

Conclusion: Long-pulsed 1064-nm Nd:YAG laser has been shown to improve KP in Thai patients compared with control after three treatment sessions.