Faint pink or reddish marks on a newborn’s skin are a type of vascular birthmark known medically as Nevus Simplex. These marks are extremely common, affecting a large percentage of infants, and are entirely benign. Colloquially, they are known by poetic names such as “angel kisses” or “stork bites,” depending on their location. These temporary marks do not signify any health issue and are a normal part of newborn development.
Identifying Salmon Patches
Nevus Simplex is characterized by a flat, irregular patch of skin that ranges in color from pale pink to a deeper reddish-purple, often described as the color of salmon. The edges of the mark are typically indistinct, blending subtly into the surrounding skin. These marks are not raised, do not change the texture of the skin, and will temporarily blanch, or fade, when gentle pressure is applied to them.
The common names used for these marks depend entirely on their location on the body. Marks appearing on the face, such as on the eyelids, between the eyebrows (glabella), or on the forehead, are often called “angel kisses.” The term “stork bite” is reserved for those patches located on the back of the neck, near the hairline, or occasionally on the posterior scalp.
The Underlying Cause
The cause of these birthmarks is not related to trauma or injury during birth. Nevus Simplex is a type of capillary vascular malformation, meaning it stems from a variation in the tiny blood vessels just beneath the skin’s surface. Specifically, the marks are caused by a localized dilation, or widening, of the capillaries in the superficial layer of the skin.
These dilated capillaries are considered remnants of fetal blood circulation that did not fully regress after birth. Because the skin of a newborn is thin, the increased blood flow through these slightly enlarged vessels becomes visible as a pink or red patch. The marks tend to occur along the midline of the body, which may reflect the developmental pathways of blood vessel formation during gestation.
The marks are dynamic and will visibly darken when blood flow to the area is increased. If the baby is crying, straining, or becomes overheated, the increased pressure or temperature causes the capillaries to expand further, making the patch more prominent. As the baby calms down or cools, the vessels constrict slightly, and the color of the patch diminishes again.
What Happens Over Time
The prognosis for Nevus Simplex is excellent, as these birthmarks are harmless and generally resolve without intervention. Marks located on the face, the “angel kisses,” have a high likelihood of fading completely, often disappearing within the first one to two years of life. This fading occurs as the baby’s skin thickens and the dilated capillaries naturally constrict or become less visible.
The patches on the nape of the neck, or “stork bites,” are more likely to persist into adolescence and adulthood, potentially in about half of the cases. Even when they do not fully disappear, they are usually covered by the child’s hair and are not a cause for medical concern. No treatment is necessary for these marks, though persistent patches can be lightened using laser therapy later in life for cosmetic purposes.
Nevus Simplex is distinct from other vascular birthmarks. For example, a hemangioma is a raised tumor of blood vessels that grows rapidly, while a port-wine stain is a permanent vascular malformation. Salmon patches do not grow larger, do not cause discomfort, and are not associated with any underlying developmental syndromes.