Adverse effects reported in pulsed dye laser treatment for port wine stains

A retrospective study was conducted over a 762-day period to investigate the incidence of adverse effects following pulsed dye laser treatment for port wine stains using the Chromos 585 nm pulsed dye laser (PDL). Treatment energy densities typically ranged from 4.0 J/cm² to 7.5 J/cm². Treatment was predominantly delivered as a 7 mm-diameter pulse of laser light, although a 5 mm pulse was occasionally used. Nine patients experienced one adverse event each, with scabbing, blistering (prolonged in one case that persisted for more than 2 months), hypopigmentation or hyperpigmentation; one of the nine patients developed both blistering and hypopigmentation. The incidence of adverse effects per treatment was 1.4% (1.7% for adults and 0.6% for children). The lower leg was the most common site for an adverse effect; four out of 22 patients (18%) receiving PDL treatment for lower leg port wine stains (PWSs) suffered an adverse effect (three cases of hyperpigmentation and one of hypopigmentation and blistering). Four patients suffered an adverse effect following an increase in the energy density of the laser treatment. There was no statistically significant correlation between laser performance and the occurrence of adverse effects.