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By the Peanutbean parent · checked against CDC, NHS and AAP guidance · how we fact-check

Newborn skin: baby acne, milk spots, heat rash, and birthmarks explained

Last verified: July 18, 2026

The short answer: new baby skin produces a parade of spots, and nearly all of them are harmless and temporary. Baby acne clears in weeks to months, milk spots (milia) go within a few weeks, and the blotchy newborn rash called erythema toxicum settles on its own. Most birthmarks fade or stay harmless. The one thing to memorise is the glass test: a rash that does not fade under a pressed glass is an emergency.

Spots that show up in the first weeks

Baby acne. Small spots and pimples on the cheeks, nose and forehead, appearing within about a month of birth. You do not need to treat it. It usually gets better after a few weeks or months on its own (NHS: Rashes in babies and children). No scrubbing, no teenage acne products, no guilt about your own hormones. It just happens.

Milk spots (milia). Tiny white or yellow spots, usually on the face. They can also affect older babies, with spots on the eyelids, forehead or nappy area. In young babies they usually go away within a few weeks and need no treatment (NHS).

The blotchy newborn rash (erythema toxicum). Red, yellow and white spots are common in the first few weeks after birth, usually on the face, body, upper arms and thighs. The rash can disappear and reappear, which is unnerving but normal, and it should get better in a few weeks without treatment (NHS).

Heat rash (prickly heat). Small raised spots, sometimes fluid-filled, with an itchy, prickly feel. It looks red on white skin and may look grey or white, and be harder to spot, on brown or black skin. It can appear anywhere on the body and can usually be treated at home by cooling your baby down (NHS). If your baby runs hot at night, our guide on what your baby should wear to sleep helps with layers.

If the spots are yellow, greasy and on the scalp, that is a different, equally harmless thing: cradle cap. And if the skin is dry, itchy and cracked rather than spotty, look at baby eczema.

Marks babies are born with

Birthmarks come in two families: vascular (extra blood vessels, usually pink, red or blue) and pigmented (extra pigment, usually brown or grey). Both types are usually harmless, and some go away on their own (AAP: Baby Birthmarks and Rashes).

• Stork bites and angel kisses (nevus simplex). Flat pink or red patches on the eyelids, forehead, back of the neck or top of the head. Up to 80 percent of babies are born with one. They usually fade by the toddler years, and darkening when your baby cries or strains is normal (AAP).
• Blue-grey patches (dermal melanocytosis). Usually on the lower back and bottom, these are the most common birthmarks in babies with highly pigmented skin, seen in the large majority of Asian and black babies. They gradually fade, many by the toddler years, and are not bruises (AAP). Worth knowing so a childminder or relative does not mistake one for an injury.
• Strawberry marks (infantile hemangiomas). Raised red or bluish marks appearing in the first few weeks, in up to 5 percent of babies. They grow fastest in the first 5 to 7 weeks, then usually shrink and fade. Because the treatable ones respond best when treatment starts early, around 1 month old, mention any hemangioma to your doctor promptly (AAP).
• Port wine stains and cafe-au-lait spots. Port wine stains are flat red marks that do not fade and grow slowly with your child. Cafe-au-lait spots are light brown, flat, and very common. One or two are nothing; a large one, more than 5, or spots in the armpits or groin should be raised with your doctor (AAP).

The AAP’s general advice is simple and worth following: point out any birthmark to your pediatrician at a checkup and let them decide if it needs watching (AAP).

The glass test, and the red flags that skip the queue

Almost everything above gets better by itself. This section is the exception list, taken directly from the NHS.

Call 999 or go to A&E now if your child is unwell with a rash and has any of these: a rash that looks like small bruises or bleeding under the skin and does not fade when you press a glass against it, a stiff neck, being bothered by light, confusion or unusual unresponsiveness, difficulty breathing (grunting, tummy sucking under the ribs, very fast breathing), pale, blue, grey or blotchy skin, lips or tongue, or sudden swelling of the lips, mouth, throat or tongue (NHS). On brown and black skin, colour changes can be easier to see on the soles, palms, lips, tongue and inside the eyelids.

Ask for an urgent GP appointment or call 111 if your child has a rash you are worried about and you are not sure what to do, feels hotter than usual, or is under 3 months old with a temperature of 38C (NHS). Our fever guide covers those thresholds in detail.

And the NHS says something we want to repeat, because it is rare for an official source to say it this plainly: as a parent, you may know if your child seems seriously unwell, and you should trust your judgement (NHS).

Keep reading

• Baby sun safety: sunscreen, shade, and staying cool
• Baby eczema: what it looks like, what helps
• Cradle cap: what helps, and when to see a doctor
• Baby fever: the thresholds that matter
• Newborn eyes: crossed eyes, sticky eye and when to worry
• All the first-year windows

Sources

• NHS: Rashes in babies and children (page last reviewed October 2024)
• AAP: Baby Birthmarks and Rashes (last updated March 2019)

Peanutbean provides general information for educational purposes only. It is not medical advice. Every baby develops at their own pace. Always talk to your pediatrician about your child’s health.