Cold Sores and Your Baby: What You Need to Know

Cold Sores and Babies
Article at a Glance
  • Cold sores are caused by one of the herpes simplex viruses, HSV-1. There's no cure for the virus, and even if you don't have symptoms or an actual cold sore, you can still spread it.
  • While rare, HSV-1 infections in newborns can be deadly, causing severe brain damage. This includes transmission during birth through the vaginal canal, or by kissing a newborn baby on the face or sharing a toy or cup.
  • You can protect your baby from a cold sore by working with your OB/GYN if you know you have HSV-1 and avoiding a vaginal birth, as well as keeping baby away from adults who have cold sores. While it is more contagious when a person has an active cold sore, remember that the virus can still spread even without one.

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Last updated April 21, 2018.

Cold sores are no big deal for adults. They’re uncomfortable and you probably don’t want one on picture day, but they’re not dangerous. However, cold sores aren’t just a minor inconvenience for babies. In fact, they can be extremely dangerous.

This post will go over everything you need to know about cold sores and babies, what to do when you have a cold sore and a newborn, and why you shouldn’t kiss a baby when you have a cold sore.

What are cold sores?

Cold sores, also called fever blisters, are small blisters on and around your lips. They’re caused by one of the herpes simplex viruses: HSV-1. That’s closely related to HSV-2, which causes genital herpes. Cold sores are typically spread by close contact such as kissing, sharing utensils, or sharing a towel with a person who has the virus.

HSV-1 is most contagious while the carrier has actual cold sores, but can also be spread by a carrier with no symptoms. There’s no cure for cold sores — the virus stays in your system forever. Cold sores are also typically untreatable. They’ll go away on their own after a few days or weeks. In certain cases, your doctor may recommend an antiviral medication to speed the healing process.

When an adult catches HSV-1, the first outbreak is often the most severe. It may involve mouth soreness, fever, aches, sore throat, and fever in addition to the blisters around your mouth. Later outbreaks are typically limited to the blisters, without the more severe flu-like symptoms.

HSV-1 can affect the genitals and HSV-2 can affect the face, so it’s important to get tested if you experience any symptoms in either area to determine which form of the virus you have.

How do cold sores affect babies?

Newborn babies’ immune systems are supported by the antibodies they get from their mothers. That means HSV-1 infections are very rare in newborns. When an infection does happen, however, it can be extremely serious.

Mature adult antibodies usually keep the virus isolated around the lips, but babies’ immune systems aren’t strong enough to contain the virus if they do get infected. The virus can spread to rest of the baby’s body, causing permanent and severe damage. It can spread to the baby’s eyes, causing ocular herpes. Left untreated, ocular herpes can cause blindness. It can spread to the baby’s brain, causing brain damage such as meningitis or cerebral palsy.

In severe cases, HPV-1 can be fatal to newborns.

Can babies get cold sores?

As mentioned above, most babies are protected by their mothers’ antibodies. However, that protection sometimes isn’t enough. Babies typically catch cold sores in one of two ways: vertical transmission or horizontal transmission.

Vertical transmission refers to transmission of the virus through the birth canal. This can happen if the mother has a genital herpes infection — remember that both HSV-1 and HSV-2 can affect the genitals. Even when the mother has no outbreak, the virus may be shed from the cells of the birth canal and infect the baby, usually through the eyes or through abrasions caused by forceps. This is the most common form of transmission for newborns.

In some very rare cases, the virus can actually be passed through the placenta to the child during pregnancy. This is called an “intrauterine infection” and can cause spontaneous abortion, growth retardation, scarring, and hydranencephaly. Intrauterine infections typically only occur when the mother is infected with HSV-1 during pregnancy.

Horizontal transmission refers to transmission from another person after birth. This is how most adults catch cold sores. A shared toy, cup, or utensil may be the culprit. A kiss from a relative or friend can also transmit the virus. Remember that you don’t have to have an active cold sore to be contagious.

Finally, HSV-1 may be transmitted through the mother’s breast milk if the mother is infected.

Protecting Your Baby from a Cold Sore

You can protect your child from vertical transmission of HSV-1 by avoiding a vaginal birth. You can work with your doctor to test for the presence of the virus in the birth canal and vagina. If the virus is present, you and your doctor may discuss the possibility of a scheduled C-section to protect your little one from exposure.

To avoid horizontal transmission, the first step is to keep your child away from contact with adults and children with cold sores. The virus is most contagious when there are actual sores. However, those with HSV-1 can be contagious even without sores. That makes prevention harder.

You may choose to discourage people from kissing your child until your little one is a few months old, but many parents find that difficult or impossible to enforce. In any case, you should always keep your child’s toys clean and have everyone wash their hands before picking up your baby to decrease the risk of HSV and other infections.

If either parent has HSV, talk to your doctor about how best to manage the risks and keep your little one safe.

I Kissed My Baby with a Cold Sore. What do I do?

The most obvious symptom of a neonatal HSV-1 infection is the appearance of sores on the mouth, tongue, gums, lips, or throat. If you see sores, you should contact your pediatrician immediately.

However, not all HSV infections will cause sores. The infection can also cause aches, fever, trouble breathing, and swollen lymph nodes. It can also appear in your little one’s eyes as redness, sores, and swelling on the eyes and eyelids. If you see any of those signs, you should seek immediate medical attention to treat the infection before it can cause permanent eye damage.

When you take your little one in for a suspected HSV-1 infection, your doctor may be able to identify it by looking at the sores. The doctor may also order tests to check for infection in your baby’s brain and liver, which may require treatment with antivirals to avoid permanent damage.

The symptoms of an HSV-1 infection are often similar to those of other, less serious infections. It can be tempting to write off minor symptoms as a cold, but remember that it’s always safer to take your child to the doctor when in doubt. HSV-1 infections can become very serious, very fast, and the damage can be permanent.

Legal Issues with Cold Sores and Babies

In some cases, transmission of the HSV virus to your child could have been avoided by appropriate medical care. For example, your doctor may be at fault if she knew that you were infected with an HSV virus and failed to discuss the possibility of a C-section, causing your little one to contract the virus. When a doctor or other health care provider’s negligence leads to your child contracting a serious infection, you may be entitled to compensation for medical expenses, pain and suffering, emotional distress, and other costs associated with your child’s injury.

If you believe your child contracted HSV due to the negligence of a doctor or other care provider, contact an experienced attorney for a free consultation to discuss your legal options.


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46 replies
  1. Anonymous
    Anonymous says:

    My grandchild will be born tomorrow and I just came up with a cold sore on my lip yesterday. Can i or should i go to the hospital? Would it be ok if I wear a mask and not kiss the baby?

  2. Amber Krosel
    Amber Krosel says:

    Hello, and congratulations on your new grandchild! I would recommend speaking with the doctor or hospital ahead of visiting, but cold sores are very contagious. Definitely do not kiss the baby, and make sure to thoroughly wash hands. A mask to cover your face may be helpful but every precaution must be taken to ensure that baby does not get your cold sore infection.

  3. Kris
    Kris says:

    I was diagnosed over 15 years ago with genital herpes. Recently, I had a baby and over the past month, I’ve noticed sores in my mouth and throat. I took caltrex and they went away. Today, I woke up and thought that I had bitten my lip. My 4 month old son was laying in bed with me and stuck his hand in my mouth touching the sore then put his hand in his mouth. I didn’t think much of it because as I said, I thought I had bit my lip. Tonight I looked at the single sore and googled it. It looks like a herpes sore. Please, can this affect my baby now? Is there anything I can do to prevent him from getting it??

  4. Amber Krosel
    Amber Krosel says:

    Hello! I would consult with your doctor as soon as possible. Make sure he or she knows about it and go from there.

  5. Anonymous
    Anonymous says:

    I have a friend who’s infant was kissed by a relative with a cold sore 20+ years ago… she became very ill, and developed cerebral palsy from it. Thank you for posting this. It is very important information.

  6. Lou chinna
    Lou chinna says:

    Hello I have a 8 month old daughter and her father wants to be able to have visited time with her but he has the hsv1 virus and some of his family members have it also. We recently had to see a referee for custody n visiting time and I was told I have to let her go with her dad. I am so upset and worried about her contracting the virus and I also have a 2 year old who is her sibling. I am being told there is nothing I can do to fight this. Please help

  7. Siya baxi
    Siya baxi says:

    I have herpes on my back. My baby is 12 days old. I am taking all precautions but when I didnt know about it I might have touched him with infected hands. I am worried as hell. I came to know about herpes five days ago. Should i be worried. I am keeping an eye on any signs of infection on him.

  8. Bunsi
    Bunsi says:

    I have HSV 1 oral which is on my lips. Will it be spread to my genital areas ? And when when i give birth to a baby will it be transmitted to the baby too ? Please reply me soon as possible.


  9. Bunsi
    Bunsi says:

    I have oral herpes which is on my lips. Will it be spread to my genital areas ? And when when i give birth to a baby will it be transmitted to the baby too ? Please reply me soon as possible.


  10. Amber Krosel
    Amber Krosel says:

    It’s best that you speak to your doctor about your concerns. Congratulations on your pregnancy!

  11. Jessica
    Jessica says:

    I have the virus as well. I just got over an infection a few days ago and I’m due to give a csection in 2 days. I’m worried I can still give my LO the virus. Should I bring this up to my doctor?

  12. Elsa
    Elsa says:

    What if someone kisses a baby on the head with a cold sore – is the virus just transmitted through lip to lip contact?

  13. Amber Krosel
    Amber Krosel says:

    Most doctors would probably not recommend this. As mentioned in the post, the virus can also get into baby’s eyes, and their immune system isn’t strong enough to handle it.

  14. Latrice
    Latrice says:

    I noticed a fever blister on a close friend mouth, and she mused my 8 week old on the cheek. I’m gong nuts, what should I do? Helppp

  15. Debra Elder
    Debra Elder says:

    I spent the day with my 8 week old grandson and kissed him on the cheek and forehead the next day I woke up with hsv1 cold sore starting on my lip and now I’m scared to death that he might get sick ! Is there any kind of early detection we can do to make sure he didn’t get the virus ? His mother has HSV2 and had a normal delivery and did not pass it to him , would her immune system help him to fight this ? I she starts taking Valtrex would it help him if he gets it through her breast milk?

  16. Jetta
    Jetta says:

    My daughter-in-law has the HSV virus and gets breakouts on her mouth and face. She has two daughters who also have it now (not from birth). My son (her husband) has developed Bells Palsy due to kissing his daughter with an active lesion on her mouth. My concern is that my other daughter-in-law is now pregnant and due to have her baby this September, 2017. My daughter-in-law with the herpes virus says there is no way this can be transferred to the new baby when she comes unless there is an active lesion. I’m trying to convince her that she should take extra cautions when holding the baby even when there is no active lesion. What can I do to convince her she needs to be extra careful?? Please help us.

  17. Shane
    Shane says:

    I have a doubt that I got infected with HSV 2.can I make a baby without transferring it to mother.please advise me

  18. Gabi
    Gabi says:

    A family member kissed my almost 4 week old on the mouth. She just got the bump of a cold sore today a small one but still one. I wiped babies mouth and hands with a wipe but now I’m so scared it’s too late. I have the cold sore virus in my system already does that mean my baby is immune to it?

  19. Rachael
    Rachael says:

    I was babysitting a 4 week old yesterday and today broke out with a cold sore. I didn’t kiss the baby. Should I inform the parents

  20. Jillian
    Jillian says:

    My son died of HSV1 at 9 days old. I had no idea I had hsv1 or that it was active during delivery. He got it the day he was born through a tiny bit of amniotic fluid he had swallowed during his first breath. Herpes is extremely dangerous and extremely contagious. Even being someone who had never had a coldsore before my son was born, my son is still dead from this unknown fact. LADIES! Talk to your freaking doctors about herpes and share this news! When my sons autopsy came back as Insemenated hsv1, even the wisest of doctors were shocked and has never heard of or seen this to happen before. Herpes is SERIOUS! I DO NOT have genital herpes, and NO hsv1 does not mean you will get hsv2.
    Btw, the article states that hav1 is genital and hsv2 is oral, which is wrong and backwards. Please for the love of childrens sake make sure this is corrected as lives are at risk!

    During the last trimester it IS an option to be tested for and to prevent and active hsv1 outbreak BEFORE your child is born.
    I had no idea until my son had been dead for two weeks before learning about this silent, deadly virus.
    I have been learning for years about this and have learned that even from day 1, even if you found out the second your child is born that they are born with hsv1- that does not mean they will survive. Herpes is dangerous and aggresive. Even babies filled with antibiotics still have a 90% chance to die. And the survivors are disabled for life.


  21. Amber Krosel
    Amber Krosel says:

    Jillian: I am so very sorry to hear about your son. What an awful feeling that must have been, but thank you for sharing this and for helping to spread awareness about the dangers of herpes around newborns. As a note, I took a look at your comment regarding HSV1/HSV2, but we had that written correctly — HSV1 is oral and HSV2 is genital, however you can have symptoms in either area. Again, very sorry for your loss. Please let us know if there’s anything we here at Safe Birth Project can do to help.

  22. Veronica
    Veronica says:

    Hi, I understand that HSV-1/oral herpes is dangerous for babies when kissed outbreak or not. Is HSV-2/genital dangerous for babies? My baby is 6 weeks old and my friend with genital herpes is visiting. Should I have her not kiss him? Should I take any other precautions? Thanks!

  23. Amber Krosel
    Amber Krosel says:

    Hi Veronica: I would suggest you speak with your doctor about any concerns. HSV-2 is most often transmitted to babies by the mother through her birth canal, if the mother has HSV-2. However, you can get genital herpes from HSV-1. It’s generally best to err on the side of caution.

  24. Anonymous
    Anonymous says:

    Hi, I broke out in a coldsore on my lip and have been kissing my four and a half month old son on the head all day as I thought it was just a sore lip, not realising it is a coldsore and now I’m worried sick. What should I do? Thanks.

  25. Sarah
    Sarah says:

    Hi, I broke out in a coldsore on my lip and have been kissing my four and a half month old son on the head all day as I thought it was just a sore lip, not realising it is a coldsore and now I’m worried sick. What should I do? Thanks.

  26. Ali
    Ali says:

    My wife is 27 weeks pregnant. She got sore cold before as well, but she just had one few days ago. We been to doctor and he said as my wife had sore cold before then we do not need to worry. What would you advice, what should we do?

  27. Ali
    Ali says:

    Sorry forgot to ask in last question, just to clear, so while baby is not born meaning in her mother womb , this virus do not affect baby? its only after baby is born then there is risk of being infected by this virus? thanks

  28. Chris
    Chris says:

    Hi Amber,

    I have a 3 1/2 month old. I recently got a cold sore on my lip and have been trying to avoid contact with her and it is the hardest thing ever. I am so scared I could give it to her that I am not even holding her at this time, which is starting to take a tole on my husband because he is doing everything. My cold sore is starting to crust over, but now I feel a tingle on my lip in another spot. I am so worried and just want this to go away. I talked to my doctor and my babies doctor and they just said not to kiss the baby. I just would never forgive myself if I spread this to her. Do you think it is ok if I hold her and just not kiss her? Since she is a little older then a newborn is it any less dangerous if she would get it? Thanks so much!

  29. Amber Krosel
    Amber Krosel says:

    You are absolutely fine holding her. I’m so sorry you’re going through this stress. Please listen to your doctor!

  30. Amber Krosel
    Amber Krosel says:

    Depending on the virus, it can be passed to baby during birth (through the birth canal). I would suggest talking to your doctor again to ease your concerns, and it never hurts to get a second opinion. Good luck!

  31. Denise Forster
    Denise Forster says:

    Hi, I suffer quite severely from cold sores, my daughter is now 5 months old and I have a cold sore. I am wearing blister plaster patches, as she’s a bit older would she more resilient? thanks. Out of everything this terrifies me as it could be me that causes her harm. 😞

  32. Carol
    Carol says:

    We have been absolutely diligent about not letting anyone kiss our baby … not at all at first and now only on her head, not near her face. She will be 6 months old next week. At what age can we stop worrying about this so much?

  33. Amber Krosel
    Amber Krosel says:

    Hi Carol, our general research shows 6 months is when baby’s immune system is developed enough to not worry as much about it, however as you know, cold sores are contagious at any age. Your best bet would be consulting with your doctor!

  34. Tracy
    Tracy says:

    Oral herpes can be caused by hsv1 or hsv2. The information you are posting is not accurate. The University of Washington has been studying the virus over 30 years. You can pass herpes with or without active outbreaks through asymptomatic shedding. Outdated info believed oral was only hsv1 and genital hsv2. On a side note…many new cases of genital herpes is from hsv1 through oral sex. Please give your readers accurate information.

    Please review theses accurate links about herpes and transmission.

  35. Jason and Ashley
    Jason and Ashley says:

    At this moment our baby is in NICU fighting for her life. We don’t know how this will turn out, and we certainly don’t know how she contracted HSV-1. We should know in another 24 hours if she will live. We rushed her to the ER the same day we brought her home. The doctor treated her very quickly, before he even knew the virus was present. We are waiting to know if she is going to live. The virus was discovered in her spinal tap. Please let your friends and family know how serious this is for newborns. We hate that it’s highly possible that our baby will face a lifetime of struggle because of this.

  36. Kirsty
    Kirsty says:

    Hi I have a cold sore on the bottom of my nose I have a 9 month old baby and iv been kissing him I didn’t realize how dangerous it could be what should I do??

  37. Kirsty
    Kirsty says:

    Help….. I have a cold sore and I’ve been kissing my 9 month old all morning I didn’t realize how dangerous it was x

  38. Catherine
    Catherine says:

    Hello. This morning I woke up with a sore that’s close to my lip but not on it. I have a 3 month old baby and I’ve been kissing her all over the face but not the lips. I spoke to my mother and she said it’s probabl from me being all stressed out and exhausted. I’m just afraid because I looked on google and I saw the word herpes under cold sore. I don’t know a lot about herpes but when I was pregnant I had been tested for stds and the doctors told me I don’t have any. So what’s up with this cold sore then. Please help me I breastfeed my baby and I don’t want her to catch it

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