Eruption Cyst Symptoms, Causes & Treatment

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Medically Reviewed
by Dr. Lara Coseo
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What Is an Eruption Cyst?

Eruption cysts (also known as eruption hematomas) are benign cysts that form on the tooth’s mucosa. They appear as bluish-purple or reddish-brown, translucent, dome-shaped lesions, bumps, or bruises in the soft gum tissue over an erupting tooth.

While eruption cysts sometimes disappear on their own, they may hurt, bleed, or become infected. If they do, surgical treatment may be necessary to drain the contents of the eruption cyst and expose the tooth so it can erupt through the gums.

The prevalence of eruption cysts is high in third molars (wisdom teeth) in adults and in primary teeth, such as the central incisors (two front teeth), in babies. An eruption cyst may also surround a permanent tooth.

Eruption Cyst in Babies (Teething)

A baby’s primary teeth form in a protective enclosure in the jawbone before they emerge through the bone, pierce the gums, and appear in the mouth. But that protective enclosure can leak fluid that accumulates in the oral cavity between the tooth and gums before the tooth erupts. 

In this case, parents may notice a bluish-purple or dark reddish-brown lesion, bump, or bruise on their baby’s teething gums. Eruption cysts usually form about four days before and up to three days after the crown of an erupting tooth emerges.

The accumulation of fluid in the dental follicle is common, and the eruption cyst will likely heal on its own. As the baby’s tooth naturally grows in, it’ll likely rupture the sac in the process. If the tooth doesn’t break through the thin layer of gum tissue within a few weeks, however, a general dentist may make a small incision to empty the contents of the cyst and expose the tooth so it can grow in.


Eruption cysts form on a tooth's mucosa. Although benign, they can be painful, may bleed, or become infected. These commonly develop in an adult's wisdom teeth and in the two front teeth of babies.

What Causes an Eruption Cyst?

An eruption cyst happens when fluid (which is sometimes mixed with blood) accumulates around an erupting tooth. Eruption cysts may seem to appear out of nowhere. Like all oral cysts, they can form from sucking on the gums.

Most eruption cysts are harmless and most cyst ruptures happen naturally. However, an eruption cyst may become infected and cause pain and bleeding. If this occurs, surgical intervention may be required.

Symptoms of an Eruption Cyst

Eruption cysts can be unsightly if not uncomfortable. Fortunately, most eruption cysts will rupture on their own without causing any pain. Here are some symptoms of an eruption cyst:

  • A bluish-purple or reddish-brown lesion, bump, or bruise over an erupting tooth
  • A tooth that is not growing in as it should
  • Bleeding, pain, or a foul smell in the mouth due to an infected eruption cyst

Eruption Cyst Treatment

There aren’t many treatment options for eruption cysts because most of them should be left alone. They will likely burst on their own. If the eruption cyst does not naturally disappear within a few weeks, a simple surgical incision may be necessary to drain the contents of the cyst. 

While this may sound scary, it’s a common procedure that’s usually done under local anesthesia and doesn’t require any downtime. The dentist may also prescribe medication to treat any possible infections in the eruption cyst.


Eruption cysts are formed when fluid accumulates around an erupting tooth. They appear as reddish-brown or bluish-purple lesions. The cysts can bleed and cause pain and bad breath. They usually go away on their own. If they don't, a simple surgical incision may be needed to drain the contents.

What does an eruption cyst look like?

An eruption cyst is typically bluish-purple, though it might appear reddish-brown if the fluid in the sac mixes with blood. It’s typically a translucent dome of soft tissue that overlays an erupting tooth, but it may also appear as a lesion or bruise.

How to prevent eruption cysts?

While there’s not much you can do to prevent eruption cysts, you can practice good oral hygiene to prevent an eruption cyst from becoming infected. Brush your teeth and gingiva twice a day, floss daily, and rinse your mouth with fluoride.

Do not poke or prod at the eruption cyst either. It’s best to leave it alone because trying to burst the cyst with germy fingers or dirty objects can lead to an infection.

Since cysts can occur from sucking, you may give your baby a pacifier or teething ring to prevent oral cysts from forming as easily.

How long do eruption cysts last?

Eruption cysts may last a few days or a few weeks but typically disappear on their own as the tooth erupts. If an eruption cyst does not go away within a few weeks, the dentist may make a small surgical incision to leak the cyst’s fluid so the tooth can break through. This is a simple procedure that doesn’t require any downtime.

Are eruption cysts painful?

Eruption cysts are typically asymptomatic and tend to go away on their own without treatment. Some eruption cysts may become painful and bleed if they get infected. In the case of an infected eruption cyst, a surgical excision may be necessary to drain the cyst, clear the infection, and relieve any pain. The dentist may prescribe medications to treat the infection and assuage uncomfortable symptoms, as well. 

How to treat an eruption cyst in a teething baby?

An eruption cyst in a teething baby will likely resolve itself within a few weeks as the baby’s tooth grows in. However, if the eruption cyst persists, the dentist may make a small incision to release the contents of the cyst and release the tooth so it can grow in properly.


Abudayyeh, Dr. “Rochester Dentist Explains Eruption Cysts in Teething Babies: Rochester, MN.” Calcagno Family Dentistry, 16 Oct. 2012,

“Dental: Teeth and Gum Care for Infants and Toddlers.” Nationwide Children's Hospital,

Dentist, Pediatric. “What Is an Eruption Cyst or Eruption Hematoma?” Pediatric Dental Center, 27 June 2012,

Dhawan, Preeti, et al. “Eruption Cysts: A Series of Two Cases.” Dental Research Journal, Medknow Publications & Media Pvt Ltd, Sept. 2012,

Riverside Dental Group. “Eruption Cysts in Teething Babies.” Riverside Dental Group, 28 Jan. 2014,

“Teething and Tooth Eruption Tampa, FL.” Tampa, FL,

“The Treatment of Oral Cysts.” Oral Cyst Treatments - Bolingbrook, IL Abscesses and Infections,

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