A milium cyst is a small, white bump that typically appears on the nose and cheeks. These cysts are often found in groups. Multiple cysts are called milia.

Milia occur when keratin becomes trapped beneath the surface of the skin. Keratin is a strong protein that’s typically found in skin tissues, hair, and nail cells.

Milia can occur in people of all ethnicities or ages. However, they’re most common in newborns.

Keep reading to learn more about milia, their causes, and what you can do to treat them.

Milia are small, dome-shaped bumps that are usually white or yellow. They’re usually not itchy or painful. However, they may cause discomfort for some people. Rough sheets or clothing may cause milia to appear irritated and red.

Cysts are typically found on the face, lips, eyelids, and cheeks. However, they can be found on other parts of the body as well, such as the torso or genitalia.

They’re often confused with a condition called Epstein pearls. This condition involves the appearance of harmless white-yellow cysts on a newborn’s gums and mouth. Milia are also often inaccurately referred to as “baby acne.”

Causes in newborns differ from those in older children and adults.

Newborns

The cause of milia in newborns is unknown. It’s often mistaken for baby acne, which is triggered by hormones from the mother.

Unlike baby acne, milia doesn’t cause inflammation or swelling. Infants who have milia are usually born with it, while baby acne doesn’t appear until two to four weeks after birth.

Older children and adults

In older children and adults, milia are typically associated with some type of damage to the skin. This may include:

Milia can also develop if the skin loses its natural ability to exfoliate. This can happen as a result of aging.

Milia types are classified based on the age at which the cysts occur or what’s causing the cysts to develop. These types also fall into primary or secondary categories.

Primary milia are formed directly from entrapped keratin. These cysts are usually found on the faces of infants or adults.

Secondary milia look similar, but they develop after something clogs the ducts leading to the skin’s surface, like after an injury, burn, or blistering.

Neonatal milia

Neonatal milia is considered primary milia. It develops in newborns and clears within a few weeks. Cysts are typically seen on the face, scalp, and upper torso. According to Seattle Children’s Hospital, milia occur in 40 percent of newborn babies.

Primary milia in older children and adults

Cysts can be found around the eyelids, forehead, and on the genitalia. Primary milia may disappear in a few weeks or last for several months.

Juvenile milia

Rare genetic disorders that affect the skin can lead to juvenile milia. These can include:

Milia en plaque

This condition is commonly associated with genetic or autoimmune skin disorders, such as discoid lupus or lichen planus. Milia en plaque can affect the eyelids, ears, cheeks, or jaw.

The cysts can be several centimeters in diameter. It’s primarily seen in middle-aged females, but can occur in adults or children of any age or either sex.

Multiple eruptive milia

This type of milia consists of itchy areas that can appear on the face, upper arms, and torso. The cysts often appear over a span of time, ranging from a few weeks to a few months.

Traumatic milia

These cysts occur where injury to the skin has occurred. Examples include severe burns and rashes. The cysts may become irritated, making them red along the edges and white in the center.

Milia associated with drugs or products

The use of steroid creams can lead to milia on the skin where the cream is applied. However, this side effect is rare.

Some ingredients in skin care and makeup products can cause milia in some people. If you have milia-prone skin, avoid the following ingredients:

  • liquid paraffin
  • liquid petroleum
  • paraffin oil
  • paraffinum liquidum
  • petrolatum liquid
  • petroleum oil

These are all types of mineral oil that may cause milia. Lanolin may also increase the formation of milia.

Your doctor will examine your skin to determine if you have milia based on the appearance of the cysts. Skin lesion biopsies are only needed in rare cases.

There’s no treatment necessary for infant milia. The cysts will usually clear up within a few weeks.

In older children and adults, milia will go away within a few months. If these cysts cause discomfort, there are treatments that can be effective in eliminating them.

They include:

  • Cryotherapy. Liquid nitrogen freezes the milia. It’s the most frequently used removal method.
  • Deroofing. A sterile needle picks out the contents of the cyst.
  • Topical retinoids. These vitamin A-containing creams help exfoliate your skin.
  • Chemical peels. Chemical peels cause the first layer of skin to peel off, unearthing new skin.
  • Laser ablation. A small laser focuses on the affected areas to remove the cysts.
  • Diathermy. Extreme heat destroys the cysts.
  • Destruction curettage. The cysts are surgically scraped and cauterized.

Milia don’t cause long-term problems. In newborns, the cysts usually go away within a few weeks after birth. While the process might take longer in older children and adults, milia aren’t considered harmful.

If your condition doesn’t improve within a few weeks, check in with your doctor. They can make sure it’s not another skin condition.