Erythema toxicum neonatorum (ETN) is a harmless and common rash that affects newborns. It presents as a collection of small, yellowish bumps surrounded by inflamed skin.

ETN does not cause any harm. It also does not require treatment, as it will resolve by itself.

This article looks at ETN, its causes, symptoms, pictures, and more.

A mother holding a baby with erythema toxicum neonatorum, a newborn baby rash.Share on Pinterest
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ETN is a rash consisting of small, yellowish spots with an irregular area of inflamed skin surrounding them.

The condition is harmless and typically clears up within 2 weeks.

According to 2022 research, most of the spots will disappear a few hours after first appearing before reappearing on another area of the body. ETN may occur on any part of the body except the soles of the feet or the palms of the hands.

ETN affects newborns. It typically occurs at birth or in the first week after birth. It may affect around 48–72% of full-term newborns. It is less common in preterm newborns weighing under 2,500 grams.

The following images show how ETN may look on a newborn.

Symptoms of ETN include:

  • multiple yellowish-white spots, some of which may contain pus
  • spots that measure between 1–3 millimeters
  • irregular inflamed areas of skin surrounding the spots
  • a “flea-bitten” appearance

A newborn may have a few spots or many, and the spots may occur in clusters or widespread across the body. However, ETN will not occur on the soles of the feet or palms of the hands.

Some other conditions that affect newborns may look similar to ETN.

Newborn acne

Newborn acne, or neonatal acne, affects around 20% of newborns. It can occur at birth or around the ages of 2–6 weeks old.

Newborn acne may appear on the face, scalp, back, or chest. It typically clears by itself within a few weeks to months.

Milia

Milia typically presents as white or yellow bumps on the skin. It is a common and harmless skin condition. The bumps can occur anywhere on the body, though they typically appear on the face.

Around half of full-term newborns may have milia. In most cases, the condition will resolve by itself by the time a newborn is 1 month old.

Epstein pearls

Epstein pearls are small cysts that are similar to milia. However, they occur on the gums and inside the mouth of newborns.

Epstein pearls also resolve on their own without treatment within a few weeks or months.

The cause of ETN is unknown. According to the American Osteopathic College of Dermatology, it may be due to immature hair follicles and sebaceous glands.

Newborns have more hair follicles compared with adults, and ETN may be a reaction to bacteria that have entered the hair follicles. This is why ETN typically does not occur on the soles and palms, as these areas do not have hair follicles.

ETN rarely affects premature infants, so more mature newborn skin may be necessary to produce the reaction that causes ETN.

Risk factors of ETN include:

  • vaginal birth
  • being born in a hot, wet climate
  • being male, according to some research

Eosinophils are a type of white blood cell that fights disease. Researchers suggest that due to a high number of eosinophils inside the spots of an ETN rash, the condition may be a minor allergic response.

To diagnose ETN, a doctor will take a medical history and perform a physical exam.

If any further examination is necessary to rule out other conditions, a doctor may take a sample from the inside of one of the pustules for laboratory testing, although this is not typically necessary.

ETN does not require treatment and typically resolves on its own within 5–14 days.

If a parent or caregiver has concerns about ETN, or to confirm it is not another condition, they can talk with a healthcare professional for a diagnosis.

ETN is a benign condition that will not cause long-term problems in a newborn. It does not cause any other symptoms in the body. It is a harmless, temporary rash that resolves by itself.

It is uncommon for ETN to reoccur. However, if the rash does return, it will likely be mild.

A doctor can give a diagnosis of ETN to provide reassurance. A parent or caregiver can also contact a doctor if they have any concerns that the newborn’s rash may be from another condition.

A person should contact a doctor if a newborn:

This section answers some frequently asked questions about ETN.

How long does it take for ETN to go away?

ETN is self-limiting, meaning it will clear by itself without treatment. It may take between 5–14 days for ETN to go away.

In some cases, ETN may reoccur 6 weeks after birth. However, the rash is typically mild and will resolve by itself again.

When does ETN start?

ETN may be present from birth, although the rash typically occurs within 1–2 days of birth, or within the first week.

If ETN occurs in premature newborns, it may not happen until a few days or weeks after birth.

ETN is a harmless and temporary skin condition that can affect newborns shortly after birth.

An ETN rash consists of yellowish-white spots surrounded by inflamed skin. It may occur on any part of the body except the soles of the feet or the palms of the hands.

ETN resolves by itself, typically within 2 weeks, and does not require any treatment. If a parent or caregiver has any concerns about a rash or skin condition in a newborn, they can contact a healthcare professional for a diagnosis.