A hemangioma is a abnormal collection of blood vessels that occur most frequently in the skin. These blood vessels can resemble a birthmark. Types include strawberry hemangiomas, which usually disappear during childhood, cavernous hemangiomas, port wine stains, and salmon patches. These all get their red color from the collection of blood vessels that form them. Many of these types disappear on their own over time. For permanent hemangiomas, some treatments include cosmetics used to conceal them, cortisone, and propranalol. A pulsed dye laser may treat port wine stains. Other treatments may also be helpful. Follow the links below to find WebMD's comprehensive coverage about what causes a hemangioma, what it looks like, how to treat it, and much more.