Hemangiomas of infancy: clinical and biological characteristics.
Hemangiomas of infancy are common in the general pediatric population, are usually easily diagnosed, and generally do not require treatment. However, a small but significant percentage of hemangiomas of infancy may develop complications, including infection or ulceration. In addition, hemangiomas located in some anatomic regions may be associated with other anomalies and therefore require more careful monitoring and earlier intervention to prevent permanent sequelae. This review focuses on distinguishing hemangiomas from vascular malformations and delineates the natural history of hemangiomas of infancy, with an emphasis on identifying those hemangiomas that require additional evaluation and closer follow-up. Current treatment modalities, including the use of systemic steroids and the pulsed-dye laser, are discussed. In addition, several conditions that often present with cutaneous hemangiomas are described, including PHACES syndrome and neonatal hemangiomatosis. Finally, an assessment is made of the current understanding of the biology of hemangioma proliferation and involution, including the role of endothelial growth factors and GLUT1, a new marker for hemangiomas of infancy.