Study authors also found that location of the birthmark and skin tone affected degree of improvement.
Researchers sought to evaluate the effectiveness of laser treatments in reducing the appearance of port wine stains (PWS) and found that lasers can lessen the appearance in the long-term, but they do not completely clear the birthmarks.1
Study authors conducted a 25-year, double-blinded, retrospective, observational, longitudinal study of patients at Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. Data were collected and analyzed using Research Electronic Data Capture (REDCap Vanderbilt University, Nashville, Tennessee). The study included 129 patients who underwent laser treatment for PWS between June 1995 and June 2021.
Some patients received more than 1 kind of laser treatment, and all treatment sessions were recorded. Color of PWS were categorized into 1 of 6 groups, ranging from light to dark. The improvement score used a numerical rating scale (NRS) with 6 categories: 0, no improvement; 1, 1%-25% improvement; 2, 26%-50% improvement, 3, 51%-75% improvement; 4, 76%-99% improvement; and 5, 100% improvement.
The improvement score was also separated into 2 categories: >50% improvement and ≤50% improvement. A good outcome was considered to have >50% improvement. A poor outcome was ≤50% improvement.
The majority of the patients in the study were male (70.54%) and median age when treatment began was 16. Each patient underwent between 27 and 66 treatments, with a median of 49 treatments. Most patients (75.97%) had a single lesion. The distribution of the PWS was primarily the S1 area (n=107, 82.95%), followed by the S2 area (n=101, 78.29%), and S3 area (n=26, 20.16%). Sturge-Weber syndrome was seen in 26 patients.
Pulsed dye laser (PDL) was used to treat most of the PWS (88.63%), followed by the 1064-long pulse neodymium yttrium-aluminum-garnet (Nd:YAG) (4.01%), and the 532 long-pulse Nd:YAG(2.63%).
Factors associated with a good outcome were being male, having Fitzpatrick skin type 3, and a higher number of laser treatments. Factors associated with a poor outcome were hypertrophic PWS, lesions on the upper eyelid or nasal tip, and a follow-up duration of greater than 180 days.
Statistically significant improvement (50%) was shown after 6 treatments and non-statistically significant improvement was seen after 9 treatments. Complete recovery was not achieved by any patients, even after 130 treatments. The most common adverse events were purpura, hyperpigmentation, and blebbing.
Laser treatments are effective in reducing appearance of PWS, but multiple sessions are necessary to achieve >50% improvement. Long-term follow-up also leads to better treatment outcomes.