Soon after delivery, almost every new mother avidly checks for the correct number of fingers and toes of her newborn. Included in this quick survey is a cursory skin evaluation. Imperfections in the skin are commonly called birthmarks. Birthmarks come in every color, shape, and size and could be composed of any type tissue. Most birthmarks are of no medical significance, but a few may signal the possibility of important internal problems.
What Is a Birthmark?
Birthmarks are composed of cells that did not migrate to their correct location during fetal development. The most common types are either composed of cells that make blood vessels and are various shades of red to purple or are composed of pigmented cells, so they range in color from beige to black.
The medical term for this most common of birthmarks is capillary nevus simplex (commonly called stork bites). These are vascular malformations that occur on the back of the head and neck. They generally are unchanged throughout life, do not require treatment, and do not portend any significant medical problems. When they occur in other areas, they are likely to gradually resolve.
Port-wine stains refer to the purplish-red color of these vascular malformations. These can occur anywhere on the skin, but they seem to be common on the face and neck. Aside from the disfiguring nature of these lesions, they occasionally may signal problems in the brain and eye. They generally darken with age and become more elevated. Treatment usually involves the use of lasers.
Mongolian spots are bluish-grey discolorations that can only be appreciated visually, since you cannot feel them. They are frequently present on the torso and legs of darkly pigmented newborns. They characteristically resolve within the first year of life. They are produced by concentrations of melanin pigment in the deeper layers of the skin.
The name of this spot appeals to Francophile (French-loving) coffee fanatics. Their color is similar to that of coffee spiked with a bit of milk. A single small lesion is of no medical significance. More that six of these spots may signal the presence of one of a number of heritable genetic diseases.
Hemangiomas are tumors of blood vessels that are often present soon after birth. These strawberry-like tumors grow and enlarge over a period of months and then slowly resolve over the next few years, leaving a scar. Sometimes resolution may not occur. In any case, these lesions cause problems when they occur on the face (near the eye), at or near an orifice, or in some other area that might be damaged by the inflammation that occurs during resolution. If extensive and occurring on the face or over the sacrum, they may signal the presence of multiple serious internal problems. If treatment is necessary, propranolol (Inderal) has been used very successfully.
The distinction between capillary and cavernous hemangiomas depends on the caliber of the vessels composing the majority of the tumor. This requires a biopsy and an evaluation by a pathologist. If they are deep enough, the overlying skin may look normal with only a large bump present. One of the problems in deciding what do about a particular congenital vascular lesion is deciding whether it is a proliferating tumor, a hemangioma, or a nonproliferating vascular malformation. The treatment and significance of each lesion is quite different. Special studies on surgically obtained specimens may be necessary to permit differentiation.
Venous malformations are masses of nonproliferating venous structures, which may occur anywhere in the body or on the skin. Occasionally, they may be closely associated with arteries, producing a direct connection of the arterial and venous system. This can be potentially quite serious. On other occasions, they may produce problems just because of a mass effect. It is not unusual for underlying structures to grow abnormally large in the affected limb. Depending on the location of the venous malformation, there are multiple approaches to obliteration of these structures aside from surgical removal.
Congenital melanocytic nevi are abnormal accumulations of pigment-producing cells in the deeper layers of the skin. Occasionally they are associated with excessive hair growth. Very large lesions have a small but measurable predisposition to develop melanomas, a very dangerous form of skin cancer.