Confocal microscopy study of neurovascular distribution in facial port wine stains (Capillary malformation)

Background/Purpose: Vascular ectasia observed in port wine stain (PWS) birthmarks might be secondary to localized reduction of neural innervation and associated loss of autonomic stimulation. Our objective was to investigate this theory and evaluate nerve density, blood vessel density and average blood vessel size in untreated and pulsed dye laser with cryogen spray cooling (PDL-CSC) treated PWS skin. Methods: Biopsy skin specimens were taken from 14 adults with a PWS, categorized by: uninvolved skin; untreated PWS skin; PWS skin with a history of good blanching, and PWS skin with a history of poor blanching both in response to PDL treatment. Seven specimens of normal, unaffected skin were used as the experimental control group. Indirect immunohistochemistry was performed on all specimens followed by confocal microscopy imaging with computer analysis to determine nerve density, blood vessel density, and average blood vessel size. Results: Nerve density was significantly decreased in all PWS sites as compared to uninvolved skin (p < 0.01). Average blood vessel diameter was larger in untreated as compared to treated PWS sites and varied between different sites within a single PWS. Conclusion: Nerve density was decreased in all evaluated PWS sites, and this may be a factor in lesion pathogenesis. PWS blood vessel size correlated with the PDL blanching response and may prove to be a useful prognostic indicator of therapeutic outcome.