My Baby Has a Bump (Sebaceous Cyst)
The short answer
A small, smooth, movable bump under your baby's skin is most likely a benign sebaceous or epidermal inclusion cyst. These are harmless collections of skin cells or oil beneath the surface and are quite common in babies and toddlers. They almost never require treatment unless they become infected or grow rapidly.
By Age
What to expect by age
Small bumps on a newborn's skin are extremely common and are usually milia (tiny white bumps caused by trapped keratin) rather than true sebaceous cysts. Milia appear on the nose, cheeks, and forehead and resolve on their own within a few weeks. True cysts in this age group are rare but can occur anywhere on the body. They feel like smooth, round, pea-sized lumps that move slightly under the skin when touched.
If a firm, painless bump appears under your baby's skin and does not go away after a few weeks, it may be a dermoid cyst or epidermal inclusion cyst. These are benign growths that form when skin cells become trapped during development. They are most commonly found on the scalp, face, or neck. They do not cause pain and usually grow very slowly or not at all. Your pediatrician can typically diagnose them with a simple physical exam.
Toddlers may develop small cysts from minor skin trauma, clogged pores, or simply as a normal variation. A bump that has been present and unchanged for months is very unlikely to be anything concerning. If the cyst is in an area where clothing or diapers rub against it frequently, it may occasionally become irritated or red, but this usually resolves with keeping the area clean and dry.
At this age, children are more prone to bumps from falls and minor injuries, which can sometimes be confused with cysts. A true cyst will feel smooth and round under the skin, be painless, and persist unchanged over weeks. If your child's cyst has been stable and is not bothering them, continued monitoring is all that is typically needed. Your doctor may recommend removal only if it becomes repeatedly infected or is in a cosmetically sensitive area.
What Should You Do?
When to take action
- A small, smooth, painless bump under the skin that moves slightly when touched
- A bump that has been present for weeks or months without changing size significantly
- Tiny white bumps on a newborn's nose or cheeks, which are likely milia and will resolve on their own
- A bump that does not bother your baby and shows no signs of redness, warmth, or tenderness
- The bump is growing noticeably over a period of weeks
- The cyst is located near the eye, on the midline of the scalp, or in an unusual location, as some cysts in these areas warrant further evaluation
- Your baby has multiple bumps appearing in a short time frame
- The bump becomes red, warm, swollen, or painful, or begins draining pus, which could indicate infection
- A bump on the midline of the head or spine that seems attached to deeper tissue, as this may need imaging to rule out a connection to underlying structures
Sources
Related Resources
Related Skin Concerns
Baby Acne (Neonatal Acne)
Baby acne is a very common, harmless condition that appears as small red or white bumps on your newborn's face, usually around 2-4 weeks of age. It is caused by maternal hormones still circulating in your baby's system and clears up on its own within a few weeks to months without any treatment.
Baby Blister on Lip from Nursing
A nursing blister (also called a suck callus) is a small, painless blister or thickened patch on your baby's upper lip caused by the friction of latching during breastfeeding or bottle feeding. It is completely harmless, does not hurt your baby, and does not need any treatment. These are very common in newborns and typically come and go in the early weeks.
Baby Chin Rash from Drooling
Drool rash is extremely common and appears as red, irritated, or slightly bumpy skin on the chin, cheeks, neck, and chest where drool sits. It is caused by the constant moisture and digestive enzymes in saliva irritating the skin. Keeping the area dry and applying a barrier like petroleum jelly before drool exposure is the most effective treatment.
Baby Dry Patches on Cheeks
Dry patches on your baby's cheeks are very common, especially during cold or dry weather. Baby skin is much thinner and more sensitive than adult skin and loses moisture easily. In most cases, regular application of a gentle, fragrance-free moisturizer is all that is needed. If patches are red, rough, or itchy, mild eczema may be the cause.
Baby Ingrown Toenail
Ingrown toenails are fairly common in babies and toddlers, especially on the big toe. Baby toenails are soft and can easily curve into the surrounding skin. Most mild cases improve with warm soaks and gentle care. If the toe becomes very red, swollen, or shows signs of infection, your pediatrician can help with treatment.
Baby Nail Peeling or Splitting
Peeling or splitting nails in babies are very common and usually harmless. Baby nails are extremely thin and soft, making them prone to peeling, especially from normal wear and moisture exposure. This typically improves as your child grows and their nails become stronger. Keep nails trimmed short and moisturize the nail area gently.