March 21, 2007 -- Port-wine stains, a type of birthmark, may redarken in the decade after laser treatment to lighten them.
Dutch doctors report that news in The New England Journal of Medicine.
The researchers included Menno Huikeshoven, MD, PhD, of the University of Amsterdam's department of plastic, reconstructive, and hand surgery.
They studied 51 people who had gotten pulsed-dye laser therapy for port-wine stains on their face and neck a decade earlier.
The patients were asked if they thought their port-wine stains were lighter, darker, or the same color as they had been immediately after laser treatment 10 years earlier.
The researchers also did objective tests to measure the color of the patients' port-wine stains before laser treatment, immediately after five laser treatments, and 10 years after laser therapy.
Most patients -- 59% -- said they were satisfied with their results.
But only 6% said they thought their stains were lighter than before laser treatment. Fifty-nine percent said their stains were unchanged since laser treatment. The remaining 35% said their stains had darkened since laser treatment.
The objective color tests showed that average port-wine stains had darkened somewhat in the decade after laser treatment but were still lighter than before laser therapy.
"Patients should be informed about the possibility of redarkening before beginning treatment," the researchers conclude.