Different types of birthmarks fall into two categories-pigmented birthmarks and vascular birthmarks. Pigmented birthmarks occur when you have more pigment on one part of your skin than another. Vascular birthmarks occur when the blood vessels beneath your skin clump together.

Not always true to their name, some birthmarks develop weeks after birth. Birthmarks can be permanent or fade over time. Some are harmless, while others may require removal for health or cosmetic reasons. Here are examples of common birthmarks in each category.

Pigmented Birthmarks

Cafe au Lait Spots

Prevalence: 18% African American infants/.3% Caucasian infants ((National Library of Medicine Bookshelf – PearlStats – “Care Au Lait Macules“))

Risk Factor: Babies with darker skin tones

These birthmarks are light to dark brown in color, affecting an estimated 10% of the population. Though most often present at birth, adults can get them as well. These common spots are flat, can have either a smooth or rough border, and are permanent. They are caused by an increase in melanin, the substance in the outermost layer of the skin that produces skin pigmentation. This type of birthmark can form anywhere on the body but is most typically found on the torso, arms, legs, and buttocks. ((Cleveland Clinic “Café-au-Lait Spots“))

A few cafe au lait spots are considered normal. Individuals with more than six of these spots may have a genetic condition such as neurofibromatosis Type 1. ((Cleveland Clinic “Café-au-Lait Spots“))

Slate Gray Nevus/Mongolian Blue Spots

Prevalence: 10% Caucasian babies, 50% Latino babies, 90-100% Asian and African babies.

Risk Factor: Babies with darker skin tones.

This nevus is a large, blue-gray birthmark that looks like a bruise. Previously referred to as Mongolian blue spot, this birthmark is common in dark-skinned babies, especially in Asians. This nevus usually appears on the lower back but can also form on the arms, buttocks, and legs. This birthmark requires no treatment and may eventually disappear. ((WebMD “What to Know About Mongolian Blue Spots“))

Moles (Congenital Melanocytic Nevi)

Prevalence: 1% of newborns.

Risk Factor: All populations

This dark-colored mole is present at birth or the first few years of life and is usually located on the limbs or trunk of the body. It affects an estimated 1% of newborns. Most moles are small but will grow with the child. Children born with this nevus, especially large ones, are at increased risk of developing cancer. ((Cinncinati Children’s Hospital – “Moles (Congenital Melanocytic Nevi)“))

Vascular Birthmarks

Hemangiomas

Prevalence: 4-5% of infants ((Yale Medicine – “Infantile Hemangiomas“))

Risk Factor: Caucasian female infants, premature infants, twins & triplets

Hemangiomas are a cluster of small, tightly packed blood vessels. This type of birthmark is pink or red and grows during the first year of life. It recedes eventually, and most children lose most of it by age ten. Treatment is not normally required. For cosmetic reasons, some hemangiomas require medication or laser treatment, mainly due to cosmetic reasons. Real physical and medical issues can arise due to hemangiomas located near the eye, in the mouth, in the throat, or near the groin. ((Mayo Clinic – “Hemangioma“))

Port-Wine Stains

Prevalence: 0.3%-0.5% Newborns ((International Journal of Dermatology and Venerology – “Severe Port Wine Stain with Significant Nodules and Alveolar Bone Invasion Leading to Restricted Mouth Opening“))

Risk Factor: All populations

This type of birthmark is present at birth and permanent. It starts out light pink but becomes red or purple over time. Port-wine stains can occur anywhere on the body but most commonly form on the face or neck. Formed by dilated blood capillaries, this birthmark can cause the skin to thicken and may become more textured with age. This birthmark may occur due to Klippel-Trenaunay-Weber syndrome or Sturge-Weber syndrome. Port-wine stains are often treated with lasers. ((Mayo Clinic – “Hemangioma“))

Salmon Patches/Stork Bites

Prevalence: 33% infants

Risk Factor: All populations

Also called stork bites or angel kisses, salmon patches are flat, red, or pink. These common birthmarks occur in 1/3 of all babies and are normally located above the hairline at the neck, between the eyes, or on the eyelids. Those on the face normally fade within eighteen months, while those at the neck do not. Salmon patches do not require treatment. ((Nicklaus Children’s Hospital – “What Are Salmon Patches?“))

Venous Malformations

Prevalence: 1%-4% of the population ((Texas Children’s Hospital – “Venous Malformations“))

Risk Factor: All populations

Caused by dilated, abnormally formed veins, these birthmarks are usually bluish in color and can appear anywhere on the body. These malformations grow slowly and will not shrink. Treatment is necessary for those with pain or impaired function. ((Mount Sanai – “Venous Malformations“))