Cold sores (herpes labialis, herpes simplex)

Cold sores, medically known as herpes labialis, is one of the most common viral infections in humans. Around 90 percent of the population are infected with the herpes simplex virus type 1, with recurring visible outbreaks occurring in around 30 to 40 percent. The initial infection usually occurs in childhood through droplet infection or direct contact, for example through kissing.

Treatment

In many cases, the initial infection goes unnoticed; in some cases, mouth sores with painful blisters in the entire oral cavity and fever occur. After the initial infection, the virus retreats along the nerve tracts to the nerve nodes in the head area, where it remains in a dormant state for life. The virus can be reactivated under certain circumstances: a weakened immune system due to a cold or other infections, stress, exhaustion, intense UV radiation, hormonal fluctuations during menstruation, fever or minor injuries in the lip area. An outbreak of cold sores occurs in several phases.

Initially, those affected feel a tingling, burning or tight sensation on the lip. Then small blisters filled with clear fluid form on a reddened background, usually at the transition between the red of the lip and the skin. The blisters are painful and can itch. After a few days they burst and a yellowish crust forms. Healing takes around seven to ten days. The disease is highly contagious during the vesicle phase.

The diagnosis is usually made clinically. In unclear cases, the virus can be detected from the contents of the blisters. A causal cure is not possible as the virus remains in the body for life. Antiviral creams with acyclovir or penciclovir should be applied at the first signs and can mitigate the course of the disease. Antiviral tablets can be taken in the event of frequent recurrences. During an active outbreak, kissing and sharing dishes should be avoided.

Sun protection for the lips can prevent UV-related outbreaks.