Cold sores are caused by herpes simplex virus and are small blisters that develop on the lips or around the mouth. They are caused by the herpes simplex virus. Cold sores usually clear up without treatment within 10 to 14 days.

Most people with recurrent herpes lip infections have two or more outbreaks (episodes) per year.

A minority of people can have six or more outbreaks per year. Infections in the mouth can be more severe and last two to three weeks.


You may not have any symptoms when you first become infected with the virus (the primary infection). An outbreak of cold sores may occur sometime later and keep coming back (recurrent infection).

If the primary infection does cause symptoms, they can be quite severe.

Swollen and irritated gums with small, painful sores in and around the mouth, this is known as herpes simplex gingivostomatitis, sore throat and swollen glands, producing more saliva than normal.

High temperature, dehydration, feeling sick (nausea), headaches.

Herpes simplex gingivostomatitis usually affects young children, but adults can also develop it. It can last 10 to 14 days, with the sores taking up to three weeks to heal. Gingivostomatitis does not usually recur after the primary infection.

Primary herpes simplex viruses are not common in Adults but they have similar presentations as above.


Recurrent cold sores usually clear up by themselves without treatment within 7 to 10 days.

Antiviral creams and other treatments are available over the counter from pharmacies without a prescription.

If used correctly, these can help ease your symptoms and speed up the healing time.

To be effective, these treatments should be applied as soon as the first signs of a cold sore appear. This is when you feel a tingling, itching, or burning sensation around your mouth. Using an antiviral treatment after this initial period is unlikely to have much of an effect.

Complications of cold sores

Cold sores are usually mild but may cause complications in rare cases. People with weak immune systems caused by illness or treatments such as chemotherapy are particularly at risk of complications.

If the infection affects the mouth or throat, dehydration sometimes occurs if drinking fluids becomes painful. Young children are particularly at risk of becoming dehydrated.

When do you get in touch with Sandsclinic?

We can certainly diagnose cold sores and recommend self-care and antiviral treatment to help. We could get you to see a specialist if there are any concerns of recurrence of skin changes.