Pigment dye lasers have been used with success in cafe-au-lait macules, ephelides, lentigines, and orange, red, and yellow tattoos. However, they are no longer recommended due to serious secondary reactions reported, including skin discoloration and purpura (66). When topical 0.05% retinaldehyde is used with the 1540 nm erbium:glass laser, the effects of the increasing dermal thickness is potentiated. In one study, half the subjects applied 0.05% retinaldehyde daily after laser treatment and for up to three months after the fifth treatment, and half applied it daily for seven months. Dermal thickness increased in all patients, with a larger increase seen in the retinaldehyde group. A statistically significant increase in forehead dermal thickness was noted in the retinaldehyde group (67).
Although laser treatment has been used in pigmentary disorders in dark skinned patients, their cautious use is warranted. Prospective studies with larger populations of Fitzpatrick phototypes IV-VI are needed to determined their safety and efficacy (68).