context: Birthmarks are colored skin spots that either are present at birth or develop shortly after birth. Birthmarks can be many different colors, including brown, tan, black, pale blue, pink, white, red, or purple. Some birthmarks are only colorations of the surface of the skin; others are raised above the surface of the skin or extend into the tissues under the skin. The cause of most birthmarks is unknown. Most of them are not inherited. Many folk tales and myths exist about the causes of birthmarks, but none of these stories have been proven to explain the true causes of birthmarks. Most birthmarks need no treatment. They usually remain stable as a child grows older. However, some areas that can resemble blood vessel tumors -- called hemangiomas -- may need treatment because of their location. For example, a raised hemangioma near a child's eye may interfere with his or her ability to see. In rare cases, birthmarks are associated with other conditions, such as growths in the liver, lungs, stomach, or intestines. There are two main categories of birthmarks -- vascular (having to do with blood vessels) birthmarks and pigmented birthmarks. Vascular birthmarks are often pink-, purple-, or red-colored skin markings that develop before or shortly after birth. Pigmented birthmarks are skin markings that are present at birth. The marks may range from brown or black to bluish or blue-gray in color. Learn more about pigmented birthmarks. The hemangioma is a common type of vascular tumor that may occur early in life and resemble a birthmark. It is usually painless and harmless and its cause is not known. Color from the birthmark comes from the extensive development of blood vessels at the site. Types of hemangiomas and birthmarks include: Strawberry hemangiomas (also called strawberry mark, nevus vascularis, capillary hemangioma, hemangioma simplex) may appear anywhere on the body, but are most common on the face, scalp, back, or chest. They consist of small, closely packed blood vessels. They may be absent at birth, and develop during the first several weeks afterward. They usually grow rapidly, remain a fixed size, and then subside. In most cases, strawberry hemangiomas disappear by the time a child is 10 years old. Some slight discoloration or puckering of the skin may remain at the site of the hemangioma. Cavernous hemangiomas (also called angioma cavernosum or cavernoma) are similar to strawberry hemangiomas but are more deeply situated. They may appear as a red-blue spongy mass of tissue filled with blood. Some of these lesions may disappear on their own -- usually as a child approaches school age. Port-wine stains are flat purple-to-red birthmarks made of dilated blood capillaries. These birthmarks occur most often on the face and may vary in size. Port-wine stains often are permanent (unless treated). Salmon patches (also called stork bites) are very common birthmarks and appear on newborn babies. These marks are small blood vessels (capillaries) that are visible through the skin. They are most common on the forehead, eyelids, upper lip, between the eyebrows, and the back of the neck. Often, these marks fade as the infant grows. Signs of red birthmarks include: Skin markings that develop before or shortly after birth Skin markings that resemble blood vessels In most cases, a health professional can diagnose a red birthmark based on the appearance of the skin. Deeper birthmarks can be confirmed with tests such as MRI, ultrasound, CT scans, or biopsies. Many capillary birthmarks such as salmon patches and strawberry hemangiomas are temporary and require no treatment. For permanent lesions, concealing cosmetics may be helpful. Topical timolol, a beta-blocker medication, can be used safely for hemangiomas that are growing. Oral corticosteroids can reduce the size of a hemangioma that is growing rapidly and obstructing vision or vital structures. A new and very promising treatment for serious hemangiomas is propranalol, a drug usually used for the treatment of high blood pressure. Port wine stains on the face can be treated at a young age with a pulsed dye laser for best results. Other treatments for red birthmarks may include: Cryotherapy (freezing) Laser surgery Surgical removal In some cases, birthmarks are not treated until a child reaches school age. However, hemangiomas are treated earlier if they compromise vital functions like vision or breathing or make the child self-conscious. Currently, there is no known way to prevent hemangiomas or red birthmarks.