Infantile Hemangioma—Mechanism(s) of Drug Action on a Vascular Tumor

Infantile hemangioma (IH), a benign vascular tumor, is the most common tumor of infancy, with an incidence of 5%–10 % at the end of the first year. The tumor displays a distinctive life cycle consisting of a proliferating phase, occurring in the first months of life, followed by an involuting phase. Thus, IH represents a unique model of postnatal vasculogenesis, angiogen-esis, and vessel regression. Traditionally, corticosteroids were the drug of choice when treat-ment of IH was indicated. In recent years, beta-blockers, most specifically propranolol, have serendipitously been shown to be an effective pharmacological treatment. This article will focus on the mechanism of action of these two drugs, the old and the new treatments, in slowing the growth and accelerating involution of IH. Infantile hemangioma (IH), a benign vasculartumor, is the most common tumor of infancy, with an incidence of 5%–10 % at the end of the first year. There is increased risk in premature neonates under the weight of 1500 g (Amir et al. 1986), in females and in Caucasians (Haggstrom et al. 2007). The tumor displays