Cold Sores

What are cold sores?

Cold sores are small blister sores, often filled with fluid, which show up around the mouth or lips. Cold sores are caused by the herpes simplex virus which is passed on through kissing or sexual contact. Typically, cold sores clear up by themselves after seven to ten days. There is no cure for cold sores.

What causes cold sores?

Cold sores are caused by the herpes simplex virus. Cold sores are contagious and easily passed on by direct or indirect contact with someone who has one. The virus lives inside the skin and is inactive most of the time. For some people, they may only ever have one cold sore, while others have outbreaks several times a year. You can get tested to check if you have the cold sore virus.

How do you catch cold sores?

You can catch a cold sore from someone who has an active outbreak of the virus. This can be through direct contact, such as kissing or sex, or through indirect contact, like sharing a towel or lipbalm. Cold sores are most contagious when the blisters burst, but the virus can be caught at any time when the cold sore is visible.

What causes cold sore outbreaks?

Outbreaks of cold sores are commonly triggered by: 

• Fatigue
• The presence of infection 
• Your period
• Direct sunlight
• Injury to the area
• Fever
• Emotional stress 
• Recovering from being unwell

How common are cold sores?

The cold sore virus affects the majority of adults. Not everyone with the virus will get visible cold sores, however, so you may never know you have it.

What are the different types of cold sore?

Cold sores can appear anywhere around the mouth or lips. The first stage is a blister, which then bursts before it crusts over. There are two types of herpes simplex virus or HSV. HSV-1 is causes cold sores and HSV-2 causes genital herpes.

Are cold sores contagious?

Cold sores are highly contagious during an outbreak. If you have a visible cold sore you should avoid kissing, sexual activity and sharing cutlery or any other items which come into contact with your mouth.

Are cold sores painful?

Cold sores are often painful and uncomfortable. They usually begin as a tingling, burning or itchy feeling around the mouth before the blister appears. You can use painkillers to help ease the pain.

Cold sores vs angular cheilitis

Angular cheilitis is slightly different to a cold sore. It only occurs in the corners of your mouth, causing dry, cracked skin which may look like a sore. Angular cheilitis is caused by a buildup of saliva which breaks down the skin’s protective barrier allowing fungus or bacteria to grow. In some cases, angular cheilitis can be a sign of vitamin deficiency. In contrast, a core sore is caused by the herpes simplex virus and can appear anywhere around the mouth or lips.

How to treat cold sores?

A cold sore will clear up on its own within seven to ten days but treatment can speed up the healing process and relieve discomfort. Antiviral creams like aciclovir or penciclovir can be used to treat a cold sore. They are most effective if they are applied as soon as you get a cold sore, for example, when you feel a burning, itching or tingling sensation. Aciclovir tablets can be prescribed by a doctor for multiple or large cold sores. Hydrocolloid gel patches are not medicated but hide the cold sore while soothing the area. You can use painkillers or anti-inflammatories, like paracetamol or ibuprofen, for pain relief but check with your doctor or pharmacist first before using them.

How to prevent passing cold sores on?

If you have a cold sore you can prevent passing them on by:  

• Avoiding touching the cold sore with your hands. You should only do this if you are applying a treatment to it.
• Wash your hands after applying cream to the cold sore, or after touching it.
• Don't share cold sore treatments with anyone else.
• Avoid kissing or any form of sexual or oral contact until the blisters have fully healed.
• Don't share cutlery, cups, cosmetics or anything which comes into contact with your mouth.
• Take extra care around newborn babies, pregnant women and anyone with a lowered immune system.

Can you cure cold sores?

There is no cure for the cold sores. The herpes simplex virus lays dormant most of the time and may cause an outbreak occasionally, if ever.

Can cold sore outbreaks be prevented?

The antiviral drugs valaciclovir and aciclovir can be taken regularly, as tablets, to reduce the likelihood of cold sore outbreaks but only if recommended by your doctor. Avoiding triggers can also help to prevent cold sores. For example, try to wear sun cream with a high SPF and UVA protection rating. Managing your stress levels and avoiding getting ill can also help.

How to speed up cold sore treatment?

Using antiviral cream or taking antiviral tablets, like aciclovir, can help to speed up the treatment of a cold sore. Holding a cold flannel or ice pack (covered in a tea towel) over the cold sore can help soothe the affected area and ease inflammation. You can ask your doctor or pharmacist about taking ibuprofen or paracetamol for pain relief. Always wash your hands before and after touching the cold sore. Drink plenty of water to stay hydrated as it will help your skin recover.

Complications of cold sores

Cold sores usually clear up by themselves in seven to ten days. You should always see a doctor if you have a large cold sore, a cluster of cold sores or cold sores that are not healing. In some cases, cold sores can cause complications in people with a lowered immune system. This includes: 

• Skin infections 
• Sores on the fingers
• Irritation and swelling in the eyes
• Dehydration 

Cold sores are dangerous for babies as their immune systems have not yet developed. Always avoid kissing babies if you have an outbreak of cold sores.

Are cold sores an STI?

Cold sores are caused by the herpes simplex virus, known as HSV-1. This is not the same as the genital herpes virus which is caused by HSV-2. The two viruses are related and are both sexually transmitted infections. Cold sores can be passed on by kissing, oral sex and sharing drinks, cutlery, towels or cosmetics like lipbalm.

Will cold sores make me ill?

The first time you have a cold sore it may cause ulcers instead of sores which look like blisters. You may feel tired and ill. Speak to your doctor or pharmacist for advice.

Can you get cold sores anywhere else?

Cold sores usually appear around the mouth or lips but you can also get them on, or spread them to, other areas of your body such as the fingers, eyes, nose, cheeks and genitals.

What triggers cold sore outbreaks?

There are many factors that can trigger an outbreak of cold sores. These include: 

• Stress and emotional upsets 
• Fatigue 
• Other infections 
• Menstruation 
• A fever 
• An injury to the affected area 
• Strong sunlight 

Why do cold sores come back?

Once you have the cold sore virus, or herpes simplex virus (HSV-1), it continues to live inside your skin. Most of the time, the virus will stay dormant but certain triggers can cause cold sores to appear every now and again.

What are the different cold sore stages?

Cold sores begin as a tingly, burning or itchy sensation before they appear. The cold sore appears and often starts to fill with fluid as it forms a blister. Then the cold sore bursts. Finally, the cold sore crusts over before disappearing.

Should I be worried if my child has cold sores?

In children, cold sores cause herpes simplex gingivostomatitis. This is caused by the same HSV-1 cold sore virus and they will carry the virus for life. The cold sore blisters can take ten to fourteen days to go away and they don’t often leave scars. Children may display the following symptoms: 

• Swollen, irritated gums 
• Dehydration 
• Fever 
• Producing more saliva 
• Headaches
• Mouth ulcers
• Blisters or sores 

If they have a cold sore ensure they wash their hands regularly and avoid picking or scratching at the sores. 

Cold sores in babies can seriously affect their health and you should contact your doctor immediately if you think your baby has a cold sore. Call 111 or check the NHS website for full details.

Are cold sores related to stress?

Stress can trigger an outbreak of cold sores. This can only happen if you already have the cold sore virus.

Are certain foods bad for cold sores?

Salty, acidic foods and spicy foods can irritate cold sores. These include:

• Citrus fruits
• Tomatoes 
• Vinegar 
• Fruit juice
• Wine 
• Salty foods

Can cold sores be passed on via kissing?

The herpes simplex virus that causes cold sores (HSV-1) can be passed on during kissing. You should avoid kissing if you have a visible cold sore or if you can feel one coming on (tingling, itching or burning sensation).

Can you catch cold sores from sharing a drink?

Cold sores can be passed on by sharing drinks, cutlery, cosmetics or towels. If you have a cold sore then avoid sharing anything you have had oral contact with.

Cold sores and breastfeeding

Cold sores in babies can cause serious harm to their health as their immune system has not developed enough to fight off the virus. If you have a cold sore, do not kiss a baby. Cold sores can be passed on during breastfeeding if you have sores around your nipples. Wait for cold sores to fully heal before having skin contact with a baby.

Are cold sores genetic?

Cold sores are not genetic, they are caused by the herpes simplex virus (HSV1). You can catch the cold sore virus when you have direct or indirect contact with someone who has an active cold sore infection

When are you no longer contagious?

When your cold sores have completely disappeared you are no longer contagious. Once the cold sore has scabbed over you are still contagious as it can still burst or leak.

Can you have oral sex if you have cold sores?

Oral sex should be avoided if you have cold sores as you can pass the virus on to the other person’s genitals. This can cause genital herpes.

Are cold sores dangerous?

While cold sores can be uncomfortable and unsightly, they are generally not dangerous for adults. Cold sores can be dangerous for babies. For people with a lowered immune system, cold sores can cause complications such as: 

• Dehydration- which is particularly common in children 
• Skin infections- usually brought on by cuts, sores or skin reactions coming into contact with the virus
• Herpetic whitlow- this is where the sores spread to your fingers 
• Herpetic keratoconjunctivitis- this affects the eyes, causing swelling, irritation and possible secondary infections