Port-wine stains are birthmarks caused by malformations of blood vessels in the skin. They manifest themselves in infancy as flat, red marks on the skin and do not disappear spontaneously but may, if untreated, become darker and thicker by middle age with a 'cobblestone appearance'.
Different lasers and light sources are used to lighten the port-wine stains by a reduction in redness. However, it is unclear which treatment gives the best results. Our aim with this systematic review was to assess the benefits and harms of the various lasers and light sources available. We found 5 randomised controlled trials, involving 103 participants, which we included in our review. All of the included trials assessed the effectiveness of the interventions using a within-participant design. These trials assessed the pulsed dye laser, intense pulsed light, and Nd:YAG laser. Only the pulsed dye laser was assessed in all five trials.
None of the studies focused on participant satisfaction which was our primary outcome. Depending upon the setting of the pulsed dye laser, more than 25% lightening (i.e. by reduction in redness) of port-wine stains occurred. This was after 1 to 3 treatments for up to 4 to 6 months postoperatively in 50% to 100% of the participants of the trials. Substantial evidence is lacking for other laser types and intense pulsed light.
Side-effects were rare in the included trials, but 3 trials reported pigmentary alterations in 3% to 24% of the participants, with the highest percentage occurring in Chinese participants with darker skin types. In one study one participant experienced scarring of the skin due to a too-high dose of the laser used. Short-term side-effects included pain, crusting, and blistering in the first two weeks after treatment. Two trials reported no occurrence of long-term adverse effects, i.e. six months after treatment.