Overview
Cold sores (herpes labialis) are among the most common viral skin infections. In most cases they are caused by herpes simplex virus type 1, less frequently by type 2. A large proportion of adults carry the virus, but not everyone develops visible outbreaks. A typical outbreak often begins with tingling, burning or a feeling of tightness on the lip. Within a few hours to days, grouped, fluid-filled blisters form, which burst, weep and then crust over. Without treatment, an uncomplicated outbreak usually heals within one to two weeks. Because the appearance is very characteristic, cold sores are well suited to telemedical visual diagnosis: in the video consultation, the doctor can assess the finding, clarify questions about the course and, following medical assessment, issue a private prescription for antiviral agents. Time matters particularly in an acute outbreak, as treatment started early can favourably influence the duration and severity of symptoms.
Common causes
Initial infection with herpes simplex viruses often occurs in childhood through close contact, for example through kissing or shared objects. After the initial infection, the viruses retreat into nerve ganglia, where they remain dormant for life. A visible cold sore outbreak occurs when the viruses become active again. Typical triggers include intense sun exposure or UV light, feverish infections such as colds, psychological or physical stress, lack of sleep, and hormonal changes, for example related to the menstrual cycle. Mechanical irritation of the lip, dental procedures, injuries and a weakened immune system can also promote an outbreak. Which triggers play a role varies from person to person. Knowing your personal triggers helps with prevention – for example through consistent UV protection for the lips, sufficient sleep and mindful handling of stressful periods.
When to see a doctor
An uncomplicated cold sore outbreak can be assessed by a doctor in the video consultation – this is particularly useful if you need an assessment early in the outbreak and, where appropriate, a private prescription. You should have an in-person examination promptly if the blisters are very extensive, spread beyond the lip to larger areas of skin, are unusually painful, or have not healed after two weeks. The same applies to frequent recurrences, a weakened immune system, pregnancy, and fever with marked malaise. Eye involvement is a warning sign: in case of redness, pain, light sensitivity or visual disturbances, you should seek ophthalmological help immediately. If high fever with neck stiffness, confusion, impaired consciousness or seizures occurs, call the emergency number 112 immediately. Special caution applies to newborns: if an infant develops blisters, poor feeding or fever after contact with an affected person, immediate medical attention is required.