Herpes simplex labialis (oral herpes), is commonly known as cold sores and is caused by the herpes simplex virus, type 1 (HSV-1)^3,4. Herpes simplex virus, type 2 (HSV-2) is mainly responsible for causing genital herpes, however, HSV-2 may spread to the mouth during oral sex which can result in oral herpes⁴.
Cold sores are a common infection of the mouth area that may affect the lips, mouth, throat or gums⁴. They are small, painful, fluid-filled blisters and may also be referred to as fever blisters^3,4. Cold sores can affect each individual differently but in most cases they are itchy, tingly and unsightly³.

The herpes virus spreads most easily from individuals who have an active outbreak of cold sores⁴. Cold sores are highly contagious and although during some stages of the cold sore outbreak you are less likely to transmit the herpes virus, the possibility of transmission is almost always present³. You can be infected with the virus if you have intimate or personal contact with an infected individual or if you touch an open cold sore or item that has been in contact with the herpes virus, such as, towels, dishes, infected razors or any other personal item^3,4.
Initial infection occurs typically in childhood or adolescence, because during childhood parents may spread the virus to their children in normal daily activities^3,4.
A cold sore typically lasts between seven and ten days. However it may last as long as two or three weeks³.

1)     Prodromal Stage (1-2 days):

• This stage is experienced by 46-60% of patients.
  The symptoms in this stage are the first signs of a cold sore and include tingling, itching, inflammation and soreness around the mouth where the cold sore will appear.
• In patients that have recurrent cold sores, the site of the blister is often the same and is usually located on the upper or lower vermilion border.
• In some cases the skin in and around the nose or on the cheeks is the target.
• Some patients may experience a fever during this stage.

2)     Blister Stage (Approximately 2 days):

• Blisters appear and are filled with clear, yellow fluid.
• Several separate blisters may appear and form a large crop on the lips that can disfigure the lips.

3)     Weeping Stage (Approximately 1 day):

• The blisters begin to rupture and expose an open wound that becomes grey in colour.
• The fluid that drains from the cold sore is yellowish and highly infective and the virus is most contagious at this stage.

4)     Scabbing/Crusting stage (2-3 days):

• A yellowish scab/crust forms and covers the open wound and the cold sore begins to heal.

The area beneath the scab remains painful and the scab can break and bleed and subsequently form a smaller secondary scab.
5)     Healing Stage (Several days):

• The secondary scab slowly becomes smaller and begins to reveal pink skin that eventually resembles the surrounding unaffected epidermis.

Cold sores eventually do heal but there is no cure for the herpes virus that causes them. Once you are initially infected with the virus it remains in your body forever3. The initial infection may often be asymptomatic and may not be noticed by the patient or by the parents (in the case of an infected child), where other patients may only notice a fever. Alternatively the initial HSV-1 infection could be the most severe and gradually become less intense with recurrence³.
After the initial infection the virus becomes dormant in the nerve tissues of the face^2,3. After time the virus may be triggered and the symptomatic cold sores reappear, this is known as recurrence³. Approximately one third of patients who experience the initial HSV-1 lesion experience recurrences³.