1 Section of Dermatology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
2 Division of Dermatology, Cooper Medical School of Rowan University, Camden, New Jersey, USA.
3 Unit on Vascular Malformations, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA.