Eruption Cysts in Children

 What Is That Bump on My Child’s Gum? If you're watching your child’s teeth come in and suddenly spot a soft bump on their gums, don't panic—it might be an eruption cyst. These fluid-filled sacs form over a tooth that’s getting ready to break through. They might look bluish or a little red but are usually harmless and painless.

 Today, we’ve asked Dr Ellie, our Brisbane Paediatric Dentist, to explain what eruption cysts are, how to spot them, and when to see a dentist.

What Are Eruption Cysts and How Do They Form?

Sometimes, just before a new tooth starts to poke through the gum, you might notice a soft, round bump in your child’s mouth. It might look a bit swollen, and the colour can be clear, bluish, or even slightly purple. These are called eruption cysts, and while they might look a little strange or even worrying at first, they’re actually quite normal.

Why Do They Happen?

As a tooth gets ready to come in, a bit of fluid can build up right above it, just under the gum. That little bubble of fluid is what forms the cyst. If your child has bumped their gums while chewing or playing, there might even be a bit of blood inside, which can make it look darker—but again, that’s usually nothing to be concerned about.

Eruption cysts are most common in babies getting their first teeth or in older kids when their adult teeth (especially molars or front teeth) start to come in. The good news is they don’t usually hurt, and they almost always go away on their own once the tooth breaks through the gum.

Unless the cyst is causing pain or seems to be stopping the tooth from coming in properly, you usually don’t need to do anything except keep an eye on it. Nature tends to take care of the rest.

What Does an Eruption Cyst Look Like?

An eruption cyst usually appears as a soft, smooth, dome-shaped bump on the gum over a tooth that is about to erupt. It may look like a small blister and can vary in colour depending on the fluid inside:

• Clear or bluish if filled with fluid
• Purplish or dark if there is blood inside (sometimes called an eruption hematoma)

Eruption cysts are typically painless, though they may feel slightly tender if irritated. While they may look concerning, they are generally harmless and go away on their own once the tooth emerges.

What Should I Do If I See an Eruption Cyst?

First of all, try not to worry. Eruption cysts might look a little strange, but they’re usually nothing to be concerned about. Most of the time, they go away all on their own once the tooth pops through the gum.

The best thing you can do is just keep an eye on it. There’s no need to poke it, try to pop it or treat it at home—just let it be.

Make sure your child is brushing gently, and avoid giving them anything too hard or crunchy to chew on that could irritate the area.

If the bump starts to look very large, seems painful, or sticks around for more than a few weeks, that’s when it’s a good idea to check in with your kids' dentist. We can take a look and make sure everything’s on track. Most of the time, no treatment is needed—but we’re always happy to give you peace of mind.

Are Eruption Cysts Dangerous?

No worries; eruption cysts aren’t dangerous. They’re actually a very normal part of how teeth come in for many children. I know they can look a bit odd—especially when they’re bluish or swollen—but most of the time, they don’t hurt and don’t cause any problems.

These little bumps usually go away on their own once the tooth pushes through the gum. In most cases, there’s nothing you need to do, and no treatment is needed.

If the bump starts to look painful, seems infected, or the tooth underneath isn’t coming in as it should, it’s always a good idea to get it checked. We’re here to make sure everything’s okay.

Are Eruption Cysts Contagious?

Eruption cysts aren’t contagious at all. They’re not caused by a virus or bacteria, so there’s no way for them to spread from one child to another—or to anyone else in the family.

They happen simply because a tooth is getting ready to come through, and a little bit of fluid builds up in the gum. It’s just part of how some kids’ teeth come in. So, there’s no need to worry about keeping your child away from others or being extra cautious around siblings. These bumps are totally harmless and only affect the child who’s teething.

Are Eruption Cysts Painful?

In most cases, eruption cysts don’t hurt at all. They might look a little scary—especially if they’re big or bluish—but the truth is, most kids don’t even notice them. Sometimes, if the cyst gets quite large or if it’s been bumped or irritated, your child might feel a bit of tenderness in the area. But even then, it’s usually pretty mild.

If your little one does seem uncomfortable or if the bump becomes red, swollen, or starts to change, it’s a good idea to check in with your dentist. We’ll have a look and make sure everything’s healing the way it should.

Eruption Cysts Causes

There are a few different reasons why an eruption cyst might pop up, and most of them are totally normal. Here’s what could be going on:

Natural Tooth Eruption

This is the most common cause. As a tooth begins to break through the gums, a small pocket of fluid can build up over it. This pressure can make the gum appear swollen or form a soft, bluish bump.

Minor Gum Trauma

Occasionally, mild injury to the gums—like bumping the area during eating or playing—can cause a small fluid-filled swelling. While not a primary cause, this trauma might contribute to cyst formation in an area where a tooth is already erupting.

Crowded Teeth or Delayed Eruption

In situations where teeth are crowded or slow to erupt, added pressure in the area can increase the likelihood of a cyst forming. This is more likely in older children with mixed dentition.

Unknown Causes

Sometimes, eruption cysts appear without any clear cause. Even in perfectly healthy gums, they can form spontaneously—and they often go away on their own without treatment.

Should I Take My Child to the Dentist for an Eruption Cyst?

In most cases, no treatment is needed – Eruption cysts usually go away on their own once the tooth breaks through the gum.

Harmless and temporary – These cysts often resolve without causing pain or long-term problems.

See a paediatric dentist if concerned – If the cyst is unusually large, painful, or hasn’t gone away after several weeks, it's best to have it evaluated.

Monitoring may be needed – A paediatric dentist may monitor a slow-erupting or impacted tooth over time, using exams or X-rays.

Rare cases may need treatment – If the cyst is blocking the tooth or if the tissue is too dense, the dentist may perform a minor procedure, such as “unroofing” (removing a small part of the gum to help the tooth erupt).

Surgical treatment is rare – Intervention is uncommon in babies and typically only done when absolutely necessary.

How Long Does It take for an Eruption Cyst to Go Away?

In most cases, eruption cysts resolve on their own within a few days to a few weeks as the tooth begins to break through the gum. The pressure from the erupting tooth usually causes the cyst to flatten or rupture naturally.

If the tooth erupts more slowly than usual, the cyst may remain longer. In these cases, a paediatric dentist can monitor the area to ensure the tooth is developing properly. Treatment is rarely needed unless the cyst is persistent, painful, or interfering with eruption.

When to Be Concerned about an Eruption Cyst and Signs of Possible Complications

If the cyst does not go away after several weeks – Eruption cysts typically go away on their own once the tooth breaks through the gum. However, if the cyst persists for more than a few weeks, it may suggest a delay in tooth eruption or another issue that needs attention. A paediatric dentist should evaluate prolonged cases to ensure the tooth is developing properly and to rule out any potential complications.

If the cyst is causing noticeable pain or discomfort – Eruption cysts are usually painless and go unnoticed by children. If your child complains of ongoing soreness or tenderness in the area, it may indicate increased pressure from the erupting tooth, irritation, or, in some cases, a possible infection. Persistent discomfort should be evaluated by a paediatric dentist to determine the cause and whether any treatment is needed.

If there is swelling, redness, or warmth around the area – Healthy eruption cysts are typically soft, non-tender, and not associated with redness or warmth. If you notice swelling, redness, or the area feels warm to the touch, it could be a sign of inflammation or a developing infection. These symptoms should be evaluated promptly by a paediatric dentist to ensure appropriate care.

If the cyst appears to be growing rapidly or is very large – While eruption cysts can vary in size, a rapidly growing or unusually large cyst may interfere with the normal eruption of the tooth or place pressure on nearby tissues. This can sometimes cause discomfort or changes in the surrounding area. A paediatric dentist can evaluate the cyst to determine if any intervention is needed to support proper tooth eruption.

If your child has difficulty eating or speaking due to the cyst – Most eruption cysts do not interfere with daily activities. However, if the cyst is large or causing discomfort, it may make chewing or speaking difficult for your child. This could impact nutrition or speech development if not addressed. A paediatric dentist should evaluate the area to determine if treatment is needed to improve comfort and function.

If there is pus or bleeding from the area – Eruption cysts are usually not associated with pus or bleeding. The presence of pus may indicate an infection, while bleeding could suggest trauma or irritation. These symptoms are not typical and should be evaluated promptly by a paediatric dentist to determine the cause and provide appropriate care.

If the tooth under the cyst seems delayed or isn't erupting as expected – If the tooth beneath the cyst is not coming in within the typical timeframe, it may be delayed or partially obstructed by overlying gum tissue. A paediatric dentist can assess the area with a clinical exam and X-rays to determine the cause. In some cases, simple monitoring is all that’s needed, but in others, a minor procedure may be recommended to help the tooth erupt properly.

If you’re unsure or concerned about the appearance of the cyst – Even if the cyst appears minor, it’s always appropriate to consult a paediatric dentist. They can determine whether it’s a normal part of the eruption process or something that requires attention. Early evaluation offers peace of mind and helps support healthy oral development.

Tips for Parents

You can help keep your child comfortable and support healthy tooth eruption with a few simple steps at home:

• Avoid poking or squeezing the cyst – Let it resolve naturally without interference.
• Use cold teething toys or a chilled washcloth to soothe any mild discomfort.
• Encourage gentle brushing around the area to maintain good oral hygiene.
• Watch for changes in the cyst’s size and colour or if your child experiences pain.
• Keep regular dental checkups so your pediatric dentist can monitor eruption and address any concerns early.

Can You Prevent Eruption Cysts?

Eruption cysts generally cannot be prevented, as they are a natural part of the tooth eruption process. These cysts form when fluid accumulates over a developing tooth as it moves through the gum. They are considered a normal developmental occurrence and are usually harmless.

While you can’t stop eruption cysts from forming, you can support your child’s overall oral health and ensure proper tooth eruption by:

• Maintaining good oral hygiene from the time the first tooth appears
• Monitoring your child’s mouth during teething for any unusual swelling or changes
• Scheduling regular dental visits, starting by age 1, as recommended by the American Academy of Pediatric Dentistry (AAPD)

Early dental checkups allow the dentist to monitor eruption patterns, provide guidance, and address any concerns promptly—even if treatment is rarely needed for eruption cysts.

What Happens Next?

In most cases, eruption cysts go away on their own without treatment. As the tooth continues to erupt and breaks through the gum, the cyst typically disappears within a few weeks.

If the cyst becomes painful, delays eruption, or shows signs of infection, a pediatric dentist may recommend a minor procedure to assist the tooth in coming through. This involves making a small incision in the gum to relieve pressure and help the tooth emerge. It’s a simple and quick treatment, but it’s rarely needed.

Who Gets Eruption Cysts?

Eruption cysts can occur in children at different stages of tooth development. They are most commonly seen:

• During the eruption of baby teeth, typically between 6 months and 3 years of age
• When permanent teeth begin to come in, usually around age 6 and older
• In some cases, eruption cysts may appear in younger infants once teething begins, but this is less common. Any unusual swelling or bumps during teething should be checked by a pediatric dentist if you’re unsure.

Key Things for Parents to Remember

• Eruption cysts are common and usually harmless. They’re just part of how teeth come in.
• They appear as a soft, possibly bluish swelling on the gums where a tooth is coming in.
• In most cases, they will disappear on their own once the tooth erupts.
• Keep an eye out for signs of discomfort or infection.
• If you're concerned, don't hesitate to chat with your dentist to get it checked out.
• Watch and Wait: In most cases, all you need to do is keep an eye on it until the tooth shows up.
• Easy Fix: If the bump causes any discomfort, simple treatments like a small incision can help, usually without the need for any strong medicine.

Supporting Healthy Teeth as They Grow

If you've noticed changes in your child's gums or teeth, Dr Ellie Nadian is here to help with clear advice and practical care. For children who feel nervous or overwhelmed at the dentist, we provide gentle sedation options—including laughing gas and sleep dentistry in Brisbane for those who need extra support.

According to Brisbane Dental Sleep Clinic, Sleep Dentistry Brisbane can turn dental appointments into more stress-free and comforting sessions.

We also offer flexible payment plans through Humm and Supercare. Call (07) 3343 4880 to book an appointment.

Disclaimer: This material is for informational purposes only and should not replace professional dental or medical advice. See a kids dentist for any concerns about your child’s teeth or gums.