Re-emergence of port wine stains following treatment with flashlamp-pumped dye laser 585 nm

Despite the advances in laser treatment of port wine stains (PWS), re-emergence of these lesions still occurs. We carried out a retrospective audit of all children that received laser treatment of PWS between 1997 and 2000 using the flashlamp-pumped dye laser with a 585-nm wavelength. Out of 110 patients treated, 15 re-emerged. The age ranged between 7 months and 15 years. Fourteen had lesions in the head and neck. Before re-emergence, a child had, on average, 6.2 sessions every 4.8 months. Lesions re-emerged on average 31.1 months following discontinuation of treatment. The natural history of an untreated PWS is to darken as the vessels become more ectatic. Therefore, it is not surprising that any residual vessels not affected by laser will continue to progress in this way, causing re-emergence of the lesion. Perhaps we should expect most or all of treated PWS to eventually re-emerge.