Infant Rash: Identifying Common Baby Rashes

The glass test

If your baby has a rash and seems unwell, press the side of a clear drinking glass firmly against the spots. If the spots fade and you can see them disappear under the glass, they are "blanching", which is reassuring. If the spots are still clearly visible through the glass (non-blanching), call 911 or your local emergency number. Do not wait for a rash to appear if your baby seems seriously ill, as meningitis can cause illness before any rash. On darker skin, look on paler areas such as the palms, soles, inside the eyelids and the roof of the mouth.

Common newborn rashes (first weeks)

Common rashes in older babies

• Diaper rash: red, sore skin on the diaper area, sparing the creases. Bright red rash in the creases with red dots at the edges suggests yeast (candida).
• Cradle cap: greasy yellow scale on the scalp, sometimes on eyebrows and behind ears. Harmless and not itchy.
• Eczema (atopic dermatitis): dry, rough, itchy red patches, starting on the cheeks and scalp and later in the creases of elbows and knees. Often from 2 to 6 months.
• Heat rash: tiny red or clear bumps on the neck, chest, back and skin folds when a baby is too warm or overdressed.
• Drool rash: red, chapped skin around the mouth and chin during teething.
• Hives: raised, itchy welts that move around over hours. Often from viral infections, sometimes from foods or medicines.

Infectious rashes

• Roseola: 3 to 5 days of high fever in a baby aged 6 months to 2 years, then a pink, blanching rash on the trunk as the fever goes. The baby usually perks up.
• Hand, foot and mouth disease: small blisters on the hands, feet and buttocks, with mouth sores and reluctance to feed.
• Viral rashes: blotchy pink rashes that blanch, often with a cold or diarrhea.
• Impetigo: sores with honey-colored crusts around the nose and mouth. Needs antibiotic treatment.
• Chickenpox: itchy spots that turn into blisters and crust, appearing in crops.
• Measles: high fever, cough, runny nose and red eyes, then a blotchy rash spreading from the face downward. Rare in vaccinated communities but rising.

Serious rashes

• Meningococcal disease and sepsis: fever, vomiting, poor feeding, drowsiness and a non-blanching rash of tiny pinpricks (petechiae) or purple blotches. A life-threatening emergency. See meningitis.
• Kawasaki disease: prolonged fever with rash, red eyes, red lips, swollen hands and feet. Needs hospital treatment to protect the heart.
• Neonatal herpes: blisters in the first weeks of life, sometimes with fever or lethargy.
• Staphylococcal scalded skin syndrome: red, tender skin that blisters and peels.

How to care for your baby's skin

• Bathe 2 to 3 times a week in lukewarm water. Daily baths can dry the skin.
• Use fragrance-free, gentle cleansers sparingly, and pat dry.
• Apply plain, fragrance-free moisturizer after baths, especially for eczema.
• Dress your baby in light layers, cotton next to the skin, and avoid overheating.
• Change diapers promptly, allow diaper-free time, and use a zinc oxide or petroleum barrier cream.
• For cradle cap, massage in a little baby oil or emollient, then gently brush away scale.
• Do not use adult creams, steroid creams or acne products on babies without medical advice.

When to see a doctor

Call your pediatrician if a rash spreads quickly, is painful, blistering, crusting or oozing, if your baby seems unwell or is feeding poorly, or if home care has not helped within a few days. A doctor will usually diagnose a rash by looking, and asking about fever, feeding, contacts, new products and vaccinations.

Frequently asked questions

When should I worry about a rash on my baby?

Seek emergency care if spots do not fade under a glass, or if your baby has a rash and is floppy, very sleepy, breathing fast, or has a high-pitched cry. Any fever of 38 °C (100.4 °F) or more under 3 months old needs same-day assessment. Most rashes in alert, feeding babies are harmless.

What does a baby rash on the face usually mean?

Small red pimples on the cheeks are usually baby acne, and tiny white dots on the nose are milia, both harmless. Rough red patches on the cheeks suggest eczema. Rash around the mouth is often drool rash. A facial rash with fever, red eyes and cough needs a doctor.

How long does a newborn rash last?

Erythema toxicum usually clears within 1 to 2 weeks, milia within a few weeks, and baby acne within a few weeks to months. These need no treatment. A rash that persists, spreads or comes with fever should be checked.

Can a baby rash be caused by formula or food?

Sometimes. Cow's milk protein or other food allergies can cause hives, swelling or worsening eczema. Hives with lip swelling, vomiting or breathing trouble need emergency care. Most rashes are not caused by food, so do not change formula without talking to your pediatrician.

Is heat rash dangerous for babies?

Heat rash itself is harmless and clears within a few days once your baby is cooler. It is a sign your baby may be overdressed or too warm, which matters because overheating is a risk factor for sudden infant death. Dress your baby in light layers.