An intradermal nevus (also called an intradermal melanocytic nevus) is simply a classic mole or birthmark. It typically appears as an elevated, dome-shaped bump on the surface of the skin.
It’s estimated that about one percent of newborns are born with an intradermal nevus.
“Nevus” refers to the mole. “Intradermal” means that the cells of the mole are located beneath the most external layer of skin. Because of this, the birthmark has the same degree of pigmentation as the surrounding skin.
In most cases, intradermal nevi appear after adolescence and are benign (noncancerous) skin growths.
An intradermal nevus often appears as a small lump on the skin, and it may have hair growig out of it. Image source: DermNet New Zealand
Intradermal nevi appear as flesh-colored bumps on the surface of the skin, though they can also appear slightly brown. In some cases, they’ll contain brown spots of small dilated blood vessels.
Intradermal nevi can appear anywhere on the skin; however, they most often show up on the scalp, neck, upper arms and legs, and neck. They can also appear on the eyelid.
The bumps are usually small, ranging anywhere from 5 millimeters (mm) to 1 centimeter (cm). In children, they’re often flat and a similar color to the person’s skin tone. Once a person reaches adolescence, the nevus usually becomes more visible. By the time a person reaches 70 years old, almost all nevi have lost much of their pigmentation.
Nevi appear raised from the surface of the skin and feel rubbery. An intradermal nevus is typically round and well-defined. It may even be hairy. It’s also possible that nevi can appear warty and dome shaped.
An intradermal nevus is the result of one of three causes:
- sun damage, especially for those with fairer skin
- immunosuppressive treatments, such as those used in cancer, which can cause more moles to develop
- genetic factors, such as your parents having a lot of moles, which makes it more likely that you will have them as too
In most cases, it’s not necessary to seek medical attention for the treatment of an intradermal nevus.
You should ask your doctor to examine any new skin growths that you’ve noticed. Always make an appointment if you notice a change in the size, shape, or color of your mole.
If the mole bothers you because of how it looks or because it catches on your clothing, you can see your doctor about treatment as well.
Unless your mole has recently changed in size, shape, or color, no treatment is necessary for an intradermal nevus. However, it is possible to remove the mole if that’s what you’d like.
Your doctor will most likely use a method called dermal electrosurgical shave excision to remove the mole, because it’s a fast and inexpensive way to remove moles.
It’s always important to monitor the size, color, and shape of your moles for potential changes.
Limiting your sun exposure helps prevent the development of more moles. It can also help prevent any changes in the moles you already have.
However, most moles are no cause for anxiety and are easily removed.