AMSTERDAM -- Port-wine stains may redarken over time after pulsed-dye laser treatments but nonetheless remain lighter than pretreatment, researchers here have found.
AMSTERDAM, March 21 -- Port-wine stains may redarken over time after pulsed-dye laser treatments but nonetheless remain lighter than pretreatment, researchers here have found.
Color of the stains significantly darkened in the decade after initial treatment (P=0.001), confirming anecdotal reports, said Menno Huikeshoven, M.D., Ph.D., of the University of Amsterdam, and colleagues. Yet the 10-year follow-up found that skin was still significantly lighter than pre-treatment (P<0.001).
The objectively measured findings support those of previous questionnaire studies and case series, they wrote in the March 22 issue of the New England Journal of Medicine.
The findings emerged from a follow-up on 51 of 89 patients in a prospective clinical trial a decade earlier who were given pulsed-dye laser treatment port-wine stains on their face or neck. They were measured after an average of five treatments.
At the long-term follow-up, the researchers again used a chromometer to measure the darkness of the stains. The 51 patients of the original cohort who consented to follow-up were similar in median age and color measurements to the full original cohort (P>0.50). Patients also completed a questionnaire.
Most follow-up patients (45 of 51) went on to have additional treatment sessions in the same hospital. These patients had an average of seven additional sessions, which were completed at an average 5.8 years prior to follow-up.
The findings at follow-up were:
Only one of the patients who thought their stains had lightened actually had an improvement, and the patients who thought their stains were unchanged actually had a 1.6 point darkening.
"Thus, patients seem to underestimate the changes in color taking place in their stains," Dr. Huikeshoven and colleagues wrote, which they said emphasizes the importance of using objective color assessment rather than questionnaires in assessing long-term outcomes.
Interestingly, there was less darkening among patients who had only the five treatments compared with those who had additional treatments (change 2.0 versus 2.5).
"However, the small number of patients precludes drawing conclusions," the researchers cautioned.
Hypothesized natural darkening with age "possibly resulting from progressive ectasia of the remaining vessels, may have a role in the redarkening of incompletely eradicated port-wine stains," they suggested.
They concluded that the positive effects of treatment are not completely durable.
"Therefore, we recommend that before commencing pulsed-dye laser therapy, all patients should be informed of the possibility of redarkening of the stain after treatment," the investigators wrote.
Newer generations of pulse-dye lasers have longer wavelengths, greater pulse energies, larger spot size, and different cooling methods than were used in the study.
"Whether treatment of port-wine stains with these new lasers will reduce the incidence of redarkening at long-term follow-up remains to be investigated," they added.