Cold Sores

Symptoms

A cold sore usually starts with a tingling, itching or burning feeling.

Over the next 48 hours one or more painful blisters will appear on your face.

Cold sore blisters are usually small and filled with fluid. The blisters can appear anywhere on the face. The blisters burst and crust over into a scab.

Cold sores should start to heal within 10 days, but are contagious and may be irritating or painful while they heal.

Certain things may trigger a cold sore, such as illness, sunshine or being on your period.

When it is not a cold sore, other possible causes of your symptoms could be due to other conditions, such as:

• Spot or boil - a painful red spot on the face filled with pus
• Mouth ulcer - Blister on the inside of the lip or mouth 
• Impetigo - Red sores or blisters on the face that become crusty, golden-brown patches

Causes

Cold sores are caused by a virus called herpes simplex.

Most people are exposed to the virus when they're children after close skin to skin contact, such as kissing, with someone who has a cold sore.

Once you have the virus, it stays in your skin for the rest of your life. Sometimes it causes a cold sore.

Treatment Options

Things you can do yourself to help with cold sores

There are things you can do to help ease cold sores while they heal and to avoid triggering a cold sore:

• avoid anything that triggers your cold sores, such as sunbeds
• use sunblock lip balm (SPF 15 or above) if you're outside in the sun
• take paracetamol or ibuprofen to ease pain and swelling (liquid paracetamol is available for children) – do not give aspirin to children under 16

• drink plenty of fluids to avoid dehydration
• do not touch your cold sore (apart from applying antiviral cream) – and if you do wash your hands before and after
• do not rub cream into the cold sore – dab it on instead
• do not eat acidic or salty food if it makes your cold sore feel worse

Treatment for cold sores from a GP

A GP may prescribe antiviral tablets if your cold sores are very large, painful or keep coming back.

Newborn babies, pregnant women and people with a weakened immune system may be referred to hospital for advice or treatment.

Prevention Tips

How long cold sores are contagious

Cold sores are contagious from the moment you first feel tingling or other signs of a cold sore coming on to when the cold sore has completely healed.

They can easily spread to other people and other parts of your body.

To help stop cold sores spreading:

• wash your hands with soap and water whenever you touch your cold sore
• do not kiss anyone while you have a cold sore
• do not have oral sex until your cold sore completely heals as you could give your partner genital herpes

When To See A Doctor

See a GP if:

• a cold sore has not started to heal within 10 days
• you're worried about a cold sore or think it's something else
• the cold sore is very large or painful
• you or your child also have swollen, painful gums and sores in the mouth (gingivostomatitis)

• you have a weakened immune system – for example, because of chemotherapy or diabetes