What are birthmarks?
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.
A birthmark (also known as nevus) is a result of a development abnormality of the skin. One possible cause is that during the embryonic stage of fetal development (first trimester), cells that belong in the mesoderm (blood forming middle germ layer) get displaced in the ectoderm (skin forming outermost cell layer). This leads to proliferation of blood vessels or abnormal pigmentation in the dermal and epidermal structures of the skin, resulting in birthmarks. Birthmarks are perceived to be non-hereditary. In addition, twice as many females as males are observed to have various forms of birthmarks. However, scientists have not yet come up with an explanation for these phenomena.
Birthmarks fall in to two main categories, vascular birthmarks, and pigmented birthmarks. Vascular birthmarks (also known as hemangioma) are made of the abnormal proliferation of tiny blood vessels (capillaries) and related to vascular skin changes. They are rarely fully-grown at birth.Hemangiomas observed to be more common among females than males, with 5 times as much females having hemangioma. Another interesting observation is that hemangiomas occur predominately in Caucasian people as opposed to dark skinned people. It has also been noted that low birth weight infants of less than 2.2 pounds have a 26% chance of being born with or developing a hemangioma shortly after.
The most common type of hemangioma is the strawberry mark, which is a red soft and elevated nub on the skin. It could either be congenital or appear shortly after birth and treatment is rarely necessary, as it will disappear on its own by the time, a child is 9-10 years of age. Salmon patches/stork bites/angels kisses are macular hemangiomas and are small, pale pink marks that appear most often on the nape of the neck, mid-forehead and the eyelids. Caused by capillaries that are visible through the skin, they most often disappear by a child's first birthday. The most noticeable and cosmetically disfiguring of all hemangiomas is the port-wine stain (nevus flammeus).
These are flat and permanent birthmarks which are composed of dilated blood vessels and normally red, blue or purple in color. They most often appear on the face, neck, and top of shoulder and less frequently around the eyes. Observed to occur in three out of every 1000 infants, they most often require medical treatment especially if they are large, lumpy, and disfiguring. Popular methods of treatment are laser surgery, steroid injections, surgical excision, and cryotherapy (freezing). If surgical excision of the nevi is impossible due to its large size then treatment must be maintained for life through laser therapy and cryotherapy, because the involvement of the nervous system will make the port-wine stain reappear.
The last type of vascular birthmarks are cavernous hemangioma. These are mostly large, red-blue benign tumors, composed of mass of connective and fatty tissue filled with large blood vessels. Fully developed at birth, they can grow up to the same size as the body part on which they appear. These are however rarely malignant and can be surgically removed if feasible.
The second main type of birthmark is the pigmented birthmark, popularly known as the café-au-lait patch for its tan-brown color. Unlike hemangiomas, these are composed of abnormal clusters of pigmented cells and not clusters of blood vessels. The pigment melanin is observed to play a role in the formation of this type of nevus. Pigmented skin lesions are permanent and most often found on the torso. Moles are the most common of this form of birthmarks. They come in all shapes, sizes, and colors and have a life cycle of about 50 years. Some are macules (flat spots), while some are conical elevated lesions or papules. Others such as Becker's nevus which is more commonly found in males is a pigmented nevus with hypertrichosis (multiple terminal hairs growing on it). Most moles are harmless and rarely pose any health risk. However, the actual risk associated with a specific nevus is still unclear. Therefore, it is feasible to get moles regularly observed and checked by a doctor, if they are particularly large, there is a sudden color change, they bleed, or become ulcerous.
A pigmented nevus present at birth such as a congenital melanocystic nevus and nevus sebaceous has a high risk of developing in to malignant melanoma (skin cancer) compared to other forms of pigmented birthmarks. Commonly located on the scalp they will develop into rougher, verrucous papules with time and must be medically observed regularly to check for any malignant tumors within the lesion. Congenital melanocystic nevi located on the scalp is also associated with seizures, mental retardation, and primal leptomeningeal melanoma if the congenital nevus is an indication of melanocytes (abnormal clusters of melanin) in the leptomeninges of the brain.A MRI must be performed to rule out any possibility. In addition to malignant melanoma, congenital café-au-lait spots might be an indication of neurofibromatosis; a rare genetic disease that causes abnormal development of nervous tissues. The presence of more than six large café-au-lait spots, particularly among children of less than 5 years is observed to be a very high possibility of neurofibromatosis.