Cold Sores in Babies: Neonatal HSV Risk | Parenting Hub
Cold sores (HSV) can be life-threatening in babies under 3 months. Learn the rules every family needs about kissing newborns.
Cold sores are a minor nuisance in adults but can be life-threatening in a newborn. No one with an active cold sore should kiss or share utensils with a baby — especially in the first three months.
Why this is serious
The herpes simplex virus (HSV-1) causes cold sores in adults. In a baby under 3 months, whose immune system is still developing, HSV can cause neonatal herpes — a severe infection that can affect the brain, liver and lungs. Even adults with no visible sore can shed the virus, but the risk is highest when a cold sore is present.
The rules
- No one with an active or healing cold sore should kiss a baby — anywhere on their body.
- Anyone with a current cold sore should wash hands before holding baby and avoid touching baby's face.
- Don't share dummies, spoons or cups.
- If you (the parent) get a cold sore, wear a mask when feeding/cuddling and don't kiss your baby until the sore has fully crusted and healed.
What infected babies look like
Blisters in clusters anywhere on the body, fever, poor feeding, unusual irritability or sleepiness. Symptoms can appear 2–12 days after exposure.
When to seek help
- Any baby under 3 months exposed to or with a cold sore — go to ED
- Blisters near baby's eyes
- Fever, lethargy, or refusing to feed
- Cluster of small fluid-filled blisters anywhere on baby's skin
Common questions
What if a relative kissed our newborn before we noticed their cold sore?
Call your GP or maternal child health line the same day. They'll assess the risk and may refer you to the ED for monitoring or testing.
I get cold sores — can I still breastfeed?
Yes, unless there's a sore on your breast. Wash hands carefully, wear a mask, and don't kiss baby until the sore has fully healed.