Postinflammatory Hyperpigmentation after Laser Treatment of Senile Lentigine, Comparing between Q-switched Ruby Laser and Q-switched Frequency Doubled Nd:YAG Laser: A Retrospective Study

Abstract

Postinflammatory hyperpigmentation (PIH) is one of the most undesirable complications after Q-switched laser treatment of senile lentigines. We conducted a retrospective study to examine the occurrence of postinflammatory hyperpigmentation after treatment of 158 cases of senile lentigines, comparing with Q-switched Ruby laser (694 nm) and with Q-switched frequency doubled Nd:YAG laser (532 nm). PIH was more frequently found after Q-switched Ruby laser treatment (64.1%), compared to Q-switched frequency doubled Nd:YAG laser treatment (47.0%) with statistically significance. Especially for the cases of the following factors as melasma, Fitzpatrick scale IV, female, darker lentigines and larger lentigines, Q-switched frequency doubled Nd:YAG laser had significantly low occurrence of PIH. Therefore, Q-switched frequency doubled Nd:YAG laser is recommended for these cases.