Childhood Illnesses

Cold Sores

A cold sore is a blister that appears on the face – usually around the mouth. They are caused by a virus called herpes simplex. Once you have the virus, it stays in your skin for the rest of your life.

You may never know that you carry the virus on your skin, in fact you will not know you have the virus unless a first cold sore blister appears.

The blisters are sore. Some people say that they get them when they are over tired or ‘run down’. People tend to get a cold sore two to six times a year after their first sore. For most people this is not serious.

Cold Sore Treatments & Stopping the Spread

Before the cold sore blister appears you may feel a tingling, burning or itching sensation around your mouth or on your lips.

If you feel this, you can start to treat the cold sore straight away before it appears. The earlier you treat the cold sore the better. You can speak to your pharmacist for advice.

Cold sores are infectious from when you feel the tingling sensation right through to when the cold sore is fully healed. This may be two weeks or longer. Applying an antiviral cream as soon as you recognise the early tingling feeling may help, but these do not work after the cold sore blisters appear.

Cold sores can be triggered by lots of things including; being unwell, having your period or exposure to sunshine.
- Use a suncream lip balm with SPF 15 or above if you are out in the sun
- Be aware of the early signs of tingling, burning or itching around the mouth or on the lips and apply an antiviral cream
- Wash your hands with soap and water before and after applying any cream
- Drink plenty of fluids to avoid dehydration and eat soft, cool foods
- Take regular Paracetamol or Ibuprofen to ease any pain and swelling (always follow the guidance for safe doses).
If you are pregnant, have a weakened immune system or your baby comes into contact with a cold sore call your GP or NHS 111 for further advice.
Wash your hands thoroughly both before and after applying any cream. Use a dabbing action to apply cream rather than rubbing it in.
- Don't kiss anyone while you have a cold sore.
- Don't touch your cold sore unless you are applying cream.
- Don't share anything that comes into contact with the cold sore such as towels, water bottles, flannels, cutlery or lip balms.
- Avoid salty or acidic foods such as crisps or vinegar. These will make the cold sore worse and might be painful.
Please see your GP or call NHS 111 for advice if;
- You are worried your baby has come into contact with a cold sore
- The cold sore has not started to heal within 10 days
- It is very large or painful
- If either yourself or your child have swollen, painful gums or any sores in your mouth.

We know that small babies are particularly at risk from this virus. It can cause ‘neonatal herpes’ which is extremely dangerous if not treated very quickly.

You may have seen on social media cases where babies have died. A baby is most at risk of getting a herpes infection in the first four weeks after birth. You should not kiss a baby if you have a cold sore to reduce the risk of spreading infection.

Cold sores and other blisters caused by the herpes virus are at their most contagious when they burst.

Who can Help?

You can contact the Healthy Child Service team by calling Just One Number on 0300 300 0123 or texting Parentline on 07520 631590. Our opening hours are 8am-6pm Monday-Friday (excluding bank holidays).

If your child is 11-24 years old, FYI Norfolk is an interactive NHS website just for them. It provides reliable and trustworthy advice and support on lots of health and wellbeing topics.

The Lullaby Trust - Baby Check App - This app has simple checks that you can do if your baby is ill and helps you think about whether they need to see a doctor or health professional.