Adverse reactions following pulsed tunable dye laser treatment of port wine stains in 701 patients.

The pulsed tunable dye laser (PTDL) is generally considered to have a very low incidence of adverse effects, allowing it to become the treatment of choice for the majority of port wine stains (PWS). The low incidence of adverse effects has led to difficulties in determining the true incidence and type of adverse effect seen with this laser. We therefore undertook a retrospective study of 701 patients with PWS, who received 3877 full treatments to determine the incidence and type of adverse effects seen following treatment with the PTDL. Blistering and crusting were seen in 5.9% an 0.7% of patients, respectively, but were transient events which usually healed without permanent sequelae. Hyper-pigmentation was the most frequently observed adverse effect seen in 9.1% of patients but generally showed gradual resolution over 6-12 months. Hypopigmentation was infrequent, seen in 1.4% of patients. The most significant adverse effects were atrophic and hypertrophic scarring seen in 4.3% and 0.7% of patients, respectively. Our observations show that there is a small but definite risk of atrophic scarring with a predisposition for younger patients. Hypertrophic scarring can occur albeit rarely and there may be predisposition towards the neck. In most cases test areas were not predictive of scarring. This underlines the need for a full discussion of scarring risk in patients with PWS undergoing treatment with the PTDL.