Newborn Rash Checker

Most of them, honestly. The big five: erythema toxicum (red blotches with tiny pale centers that migrate around the body in the first days — up to half of newborns get it), milia (pearly white pinhead bumps on the nose and cheeks), baby acne (small pimples appearing at 2 to 4 weeks as maternal hormones pass through), cradle cap (greasy yellowish scalp scales), and heat rash (fine prickly bumps in sweaty folds). Add the normal dry peeling of the first week or two, and simple diaper rash, and you've covered the great majority of newborn skin surprises. None of these needs treatment beyond gentle basics, all of them clear on their own, and none of them makes a baby unwell — which is the key: a normal rash lives on a baby who feeds, sleeps, and behaves normally. The checker above is built on that principle: the baby's condition and a few danger features matter more than perfectly naming the rash.

Press the side of a clear glass (or a fingertip) firmly against the rash and watch through it. Almost all harmless rashes blanch — the redness fades under pressure because it's blood in dilated surface vessels, which pressure empties. Spots that stay dark under the glass — non-blanching, pinpoint red-purple dots (petechiae) or larger bruise-like patches (purpura) — mean blood has leaked out of vessels into the skin, and in an infant that's an emergency sign until proven otherwise: it can signal a serious bloodstream infection (including meningococcal disease) or a blood-clotting problem. The rule is deliberately blunt: a non-blanching rash in a baby = emergency care now, whatever else seems fine. One honest caveat: the test can be hard to read on small dots or darker skin — if you can't tell, and especially if your baby has a fever or seems unwell, treat it as non-blanching and get seen.

Because in the first weeks of life, clustered blisters or fluid-filled bumps (vesicles) can be neonatal herpes (HSV) — an infection that is rare but genuinely dangerous for a newborn, and very treatable if antiviral medicine starts early. A baby can catch HSV during birth even when the mother has never had a known cold sore or any symptoms, and after birth from a kiss by anyone with an active cold sore — which is why the 'no kissing a newborn with a cold sore' rule is real medicine, not fussiness. The practical rule this checker enforces: blisters or vesicles in a baby under about 6 weeks get same-day emergency assessment — call the pediatrician immediately or go to the ER, and mention any cold-sore contact. Most skin bumps in newborns are not HSV, and clinicians would far rather check ten harmless rashes than miss one — this is the definition of better-safe.

Ordinary diaper rash — flat redness on the rounded skin that touches the diaper — responds within days to frequent changes, gentle cleaning, air time, and a thick zinc-oxide barrier cream. Patterns that deserve a pediatrician's look: a rash that's bright beefy-red and prominent in the skin folds (the creases ordinary diaper rash tends to spare), often with small satellite spots beyond the main patch — the classic look of a yeast (candida) rash, which needs an antifungal cream rather than more barrier paste; a rash with pus, weeping, crusting, or blisters (possible bacterial infection); rash plus fever; a very raw, broken-skin rash; or any diaper rash that just won't clear after several days of textbook care. And the location rule still applies: spots that don't blanch, wherever they are — including the diaper area — are the emergency kind, not the diaper kind.

Think of it as rash plus anything systemic. Rash plus fever tops the list — and in a baby under 3 months, a rectal temperature of 100.4°F (38°C) or higher is an emergency all by itself, rash or no rash. Rash plus a baby who's unusually sleepy, floppy, feeding poorly, or hard to wake. Rash plus breathing changes or swelling of the lips, tongue, or face — a possible allergic emergency where you call 911. A spreading area of hot, swollen, tender skin — possible cellulitis, which moves fast in infants — especially around the eyes or the umbilical cord stump, two locations where skin infection is always urgent. And the two standalone emergencies from earlier: non-blanching spots, and blisters in the first weeks. Everything on this list outranks any reassuring feature of the rash itself — a baby who seems ill with a rash gets seen now, even if the rash 'looks like' something harmless.

Yes, and by design. This checker runs entirely in your browser: your answers are evaluated on your own device and are never sent to a server, saved, or shared — close the tab and they're gone. That's also why there's deliberately no photo upload: a photo of your baby is exactly the kind of data that shouldn't sit on a website's server, and rash photos are genuinely hard to judge remotely anyway — lighting, skin tone, and texture all mislead. What you get back is general educational information based on AAP HealthyChildren and MedlinePlus guidance; it is not a diagnosis of your baby's rash. If your pediatrician's practice offers a secure portal, that's the right place for photos; and for anything the checker flags, an in-person exam is the answer.