A reference chart of the most common newborn rashes — from harmless erythema toxicum to congenital dermal melanocytosis — plus the non-blanching rash red flag every parent must know.
Newborn skin does a lot of adjusting in the first weeks of life. Most spots, blotches, and rashes are completely harmless and resolve without any treatment. But one pattern — a non-blanching rash — is a genuine emergency that every parent should know how to identify.
This article covers both: the benign rashes that are normal, and the one red flag that isn't.
The red flag first: non-blanching rash
Before the reference chart, this is the most important information on this page.
A non-blanching rash is one where the spots do not turn white when pressed. Petechiae (tiny pinpoint red or purple spots) and purpura (larger bruise-like patches) are the most common forms. They appear because blood has leaked out of capillaries into the skin — they cannot be pressed back into the vessels.
A non-blanching rash alongside fever, stiff neck, sensitivity to light, or a very unwell child is a medical emergency. It can be a sign of meningococcal disease (bacterial meningitis and septicaemia).1
The glass test
Press a clear glass or the side of a clear cup firmly against the rash. Look through the glass.
- If the spots fade or disappear under pressure → blanching rash. Still worth monitoring, but not the same emergency.
- If the spots remain visible through the glass under pressure → non-blanching rash. Call 999 (UK) or 911 (US) immediately. Do not wait.1
If you see a non-blanching rash alongside a sick baby: Do not drive yourself. Call 999/911. Meningococcal septicaemia can progress to life-threatening within hours — speed of treatment is critical.1
A non-blanching rash can also occur from something harmless (like the skin trauma of forceps delivery, or straining during crying) — but you cannot safely assume this without medical assessment. Always call.
Common benign newborn rashes
| Rash | What it looks like | When | Cause | Needs treatment? |
|---|---|---|---|---|
| Erythema toxicum | Yellow-white papules or pustules on a red base; blotchy red patches | Days 1–5, rarely persists past 2 weeks | Unknown; very common (~50% of term babies) | No — resolves on its own |
| Milia | Tiny white or yellow dots, 1–2mm, on nose/cheeks/chin | At birth or within days | Trapped keratin | No — clears in weeks |
| Baby acne (neonatal acne) | Red pimples, cheeks/nose/forehead | 2–6 weeks of age | Maternal hormones | No — clears by 3–4 months |
| Miliaria (heat rash) | Tiny clear or red bumps, often on torso and neck | Hot weather or overdressing | Blocked sweat ducts | No — remove excess layers; resolves quickly |
| Neonatal cephalic pustulosis | Pustules on face/scalp | First weeks of life | Malassezia yeast reaction | No — resolves on its own |
| Congenital dermal melanocytosis | Flat blue-grey or blue-green patches, often on lower back/buttocks | Present at birth | Melanocytes migrating during fetal development | No — usually fades by school age |
| Salmon patches / stork bites | Flat pink or red patches; often on nape of neck, eyelids, forehead | Present at birth | Dilated capillaries | No — most fade by 18 months; neck patches may persist |
More about each rash
Erythema toxicum
Erythema toxicum neonatorum is the most common newborn rash, appearing in up to half of all term babies.2 It looks alarming — yellow-white bumps on angry red blotches — but is completely benign. It tends to appear on the trunk, face, and limbs, sparing the palms and soles, and typically fades within 5–14 days. No treatment is needed. The cause is not fully understood but is thought to involve the immune system responding to skin colonisation.
Milia and baby acne
Both are covered in detail in Baby acne and milia. Short version: milia are trapped keratin dots present at birth; baby acne is hormonal pimples arriving at 2–6 weeks. Both resolve without treatment.
Miliaria (heat rash, prickly heat)
Miliaria occurs when sweat glands become blocked, trapping sweat under the skin. The result is tiny clear bubbles (miliaria crystallina) or small red bumps (miliaria rubra). It is most common in hot weather or when a baby is overdressed. Treatment is simply cooling the baby down and removing excess layers. It resolves within hours to a few days.2
Congenital dermal melanocytosis
Previously called "Mongolian spots," this term has been deprecated due to its association with racial prejudice. The current correct term is congenital dermal melanocytosis. These are flat, blue-grey to blue-green patches most commonly on the lower back, buttocks, and sometimes the legs or arms. They occur when melanocytes (pigment cells) don't complete their migration from the neural crest to the skin during fetal development.3
They are more common in babies of African, Asian, Hispanic, and Indigenous heritage. The patches are entirely harmless and not associated with any underlying condition. Most fade significantly by school age, though some persist into adulthood. It is important that these are documented in the baby's medical record at birth to avoid confusion with bruising.
Salmon patches / stork bites
These flat pink or red patches are caused by dilated superficial blood vessels (capillary malformations). They occur on the nape of the neck ("stork bite"), on the eyelids, and between the eyebrows. Most facial patches fade by 18 months. Neck patches are more likely to persist but are usually covered by hair.2
When to call your doctor (beyond the non-blanching emergency)
See your GP or health visitor if:
- You're unsure what type of rash your baby has
- Any rash is accompanied by fever in a baby under 3 months (a baby under 3 months with a temperature of 38°C/100.4°F or above requires same-day assessment)
- The rash appears infected: increasing warmth, swelling, crusting, weeping, or pus
- Your baby seems unwell alongside any rash — unusually drowsy, not feeding, irritable beyond what you'd expect
← Back to the complete guide: Baby health basics
Also in this cluster: Diaper rash · When to call the doctor
Sources
- NHS. "Meningitis." NHS, 2023. https://www.nhs.uk/conditions/meningitis/
- American Academy of Pediatrics (AAP) / HealthyChildren.org. "Newborn Skin: Part 2." HealthyChildren.org, 2022. https://www.healthychildren.org/English/ages-stages/baby/bathing-skin-care/Pages/Newborn-Skin-Part-2.aspx
- NICE. "Bacterial Meningitis and Meningococcal Disease in Under 16s: Recognition, Diagnosis and Management." NICE Guideline NG51, 2023. https://www.nice.org.uk/guidance/ng51
Footnotes
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NHS. "Meningitis." NHS, 2023. https://www.nhs.uk/conditions/meningitis/ ↩ ↩2 ↩3
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American Academy of Pediatrics (AAP) / HealthyChildren.org. "Newborn Skin: Part 2." HealthyChildren.org, 2022. https://www.healthychildren.org/English/ages-stages/baby/bathing-skin-care/Pages/Newborn-Skin-Part-2.aspx ↩ ↩2 ↩3
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NICE. "Bacterial Meningitis and Meningococcal Disease in Under 16s: Recognition, Diagnosis and Management." NICE Guideline NG51, 2023. https://www.nice.org.uk/guidance/ng51 ↩