Birthmarks are colored skin patches or raised areas that are either present at birth or appear within the first few weeks of life. They fall into two broad categories: pigmented birthmarks, caused by clusters of pigment cells, and vascular birthmarks, caused by blood vessels that didn’t form typically. Pigmented types are more common, accounting for about 65% of birthmarks, while vascular types make up roughly 26%. Each type has a distinct look, and knowing the differences helps you identify what you’re seeing on your own or your child’s skin.
Pigmented Birthmarks
Pigmented birthmarks get their color from melanin, the same pigment that determines skin tone. They range from barely noticeable tan patches to dark brown or black raised spots.
Café-au-Lait Spots
These are light tan or light brown spots, usually oval in shape with smooth edges. The name literally means “coffee with milk,” which describes the color well. They’re flat against the skin and can appear anywhere on the body. A single spot is extremely common and harmless. Six or more spots larger than 1.5 centimeters (or larger than 0.5 centimeters in children under age 5) can signal a genetic condition called neurofibromatosis, which warrants further evaluation.
Slate Gray Nevi
Previously called Mongolian spots, these birthmarks look bluish or gray-green, almost like a bruise. They appear most often on the buttocks and lower back, though they sometimes show up on the trunk or arms. They’re flat, can be several inches across, and are especially common in babies with darker skin tones. Unlike a bruise, they don’t change color over days or feel tender. Most fade on their own during early childhood.
Congenital Moles
Congenital melanocytic nevi are moles present at birth. They appear as raised growths that can be skin-colored, brown, or black. Some are small enough to overlook, while others cover a large area. Larger congenital moles carry a slightly increased risk of developing into skin cancer later in life, so keeping an eye on any changes in size, shape, or color over the years is important.
Vascular Birthmarks
Vascular birthmarks result from blood vessels grouped together near the skin’s surface. Their color comes from the blood itself, so they tend to be pink, red, or purple.
Salmon Patches, Angel Kisses, and Stork Bites
These are the most common birthmarks in newborns. They look like flat, pink-to-red patches and go by different nicknames depending on where they show up. A patch on the forehead, nose, upper lip, or eyelid is often called an “angel kiss.” A patch on the back of the neck is typically called a “stork bite.” Many providers consider all of these the same thing: a nevus simplex, regardless of location.
Angel kisses on the face usually fade within the first year or two. Stork bites on the back of the head or neck are less predictable. Some disappear in toddlerhood, others stick around into adulthood, often hidden by hair. They tend to become more visible when a baby cries or gets warm, then fade again at rest.
Port-Wine Stains
A port-wine stain starts as a flat, smooth patch that’s pink, red, or purple. It can appear anywhere but is most common on the face, arms, and legs. Unlike salmon patches, port-wine stains don’t fade on their own. They grow proportionally as the child grows.
The appearance changes with age. In infants and young children, the mark is smooth and flat. Over the years it often darkens, shifting from pink toward deep red or purple. The texture can thicken too, eventually feeling like small pebbles under the skin, and the surface may become raised and bumpy rather than flat. Without treatment, these changes tend to progress over decades. In rare cases, a port-wine stain on the face may be associated with Sturge-Weber syndrome or Klippel-Trenaunay syndrome, conditions that require ongoing medical monitoring.
Hemangiomas
Hemangiomas are the birthmarks that can look the most dramatic. They’re not always visible at birth. Instead, they typically appear within the first few weeks of life as a small red or bluish area, then grow rapidly during the first four to six months. At their peak, superficial hemangiomas are bright red and raised, which is why they’re sometimes called strawberry marks. Deeper hemangiomas may look bluish and sit under the skin with a soft, spongy feel.
The good news is that hemangiomas are self-limiting. After the rapid growth phase in the first year, they gradually shrink and lose their red color. About 50% resolve by age 5, and 70% resolve by age 7. The remainder may take an additional three to five years to fully flatten. Some leave behind faintly discolored or slightly textured skin where the hemangioma once was. Large hemangiomas, those along the midline of the body, or those covering an entire segment of skin are more likely to need medical attention during the growth phase.
How to Tell Birthmarks Apart at a Glance
- Flat and tan or brown: likely a café-au-lait spot or, if very light, a normal skin variation.
- Flat and bluish, on the back or buttocks: likely a slate gray nevus.
- Flat and pink or red: likely a salmon patch if it blanches when pressed, or a port-wine stain if the color is deeper and persistent.
- Raised, bright red, appeared in the first weeks of life: likely a hemangioma.
- Raised, brown or black, present since birth: likely a congenital mole.
Color alone doesn’t always tell the full story. A birthmark’s texture (flat versus raised versus bumpy), whether it blanches when you press on it, and how it changes over time are all useful clues. Vascular birthmarks tend to lighten briefly with pressure because blood is temporarily pushed away. Pigmented birthmarks don’t change with pressure at all.
Changes Worth Watching
Most birthmarks are completely harmless. A few patterns, though, are worth paying attention to. Multiple café-au-lait spots in a young child, especially six or more, can point to an underlying genetic condition. A congenital mole that changes in color, border, or size over time deserves a closer look from a dermatologist, particularly if it was large to begin with. A hemangioma that grows very rapidly, bleeds, or sits near the eyes, nose, or mouth may need treatment during its growth phase to prevent complications.
Port-wine stains on the upper face, especially around the forehead and eyelid, occasionally signal deeper involvement with blood vessels in the brain or eye. And any birthmark that becomes painful, ulcerates, or looks dramatically different from one month to the next is worth having evaluated, regardless of type.