Cold Sores (Herpes Labialis)
- Nina K
- Jun 28
- 3 min read
Cold sores, also known as herpes labialis, are caused by the herpes simplex virus type 1 (HSV-1). These are small blisters that typically appear around the lips or mouth and can recur several times a year.
What causes cold sores and how do they spread?
The virus spreads through close contact such as kissing, sharing cups, utensils, or towels. Even when symptoms are not visible, the virus can still be transmitted. Most people are infected during childhood or adolescence and carry the virus in a dormant state in their nervous system.
Who gets cold sores?
Anyone can be affected. Stress, sun exposure, illness, or dental procedures can trigger an outbreak. Some people experience just one or two episodes in their lifetime, while others have frequent recurrences.
Symptoms of a cold sore outbreak
Tingling or burning around the lips (prodrome)
Small fluid-filled blisters
Crusting and healing within 7–10 days
Sometimes accompanied by fever, sore throat, or swollen lymph nodes (especially during the first episode)
Is the virus permanent?
Yes. Once infected, HSV-1 remains in the body for life, lying dormant in the nerves. It can reactivate later, especially during stress, illness, or sun exposure. Not everyone experiences frequent recurrences.
Can it become serious?
In most cases, cold sores are mild and self-limiting. However, in rare cases, the virus can lead to complications:
Eye infections (herpes keratitis) that can affect vision
Skin infections (e.g., eczema herpeticum) in people with certain skin conditions
Very rarely, brain infection (encephalitis) or hepatitis, mainly in immunocompromised people
Can you treat or diagnose it at home?
Yes, in mild and familiar cases:
Use over-the-counter creams like Zovirax cream
Apply cold compresses to reduce discomfort
If you've been prescribed antivirals in the past, take them at the first signs (tingling) However, if it's your first outbreak, severe symptoms, or you're unsure — it's best to consult a doctor.
Can cold sores spread to other areas of the face?
Yes, although usually localized, the virus can spread to nearby areas such as the chin, nose, or cheeks, especially if the blisters are touched and the virus is transferred. Maintaining good hygiene helps prevent this.
When to seek treatment?
If this is your first outbreak, or if symptoms are severe (such as pain that prevents eating), you may benefit from antiviral medications. These are most effective when taken within 72 hours of symptom onset.
Available antiviral treatments
Acyclovir (Zovirax) or Valacyclovir (Valtrex) – taken orally
These reduce pain, shorten healing time, and lower the risk of spreading the virus
Not usually needed for mild cases
What to do for recurring outbreaks?
Mild: no treatment or pain relief with topical creams
Moderate: start antiviral tablets as soon as you feel tingling or burning
Frequent/severe: consider daily suppressive therapy with antivirals
Can you prevent outbreaks?
Use sunscreen on lips before sun exposure
Manage stress and avoid known triggers
In high-risk procedures (e.g., cosmetic lasers or facial surgery), preventive antivirals may be prescribed
Is cold sore contagious?
Yes. It is important to avoid kissing, sharing lip products or drinks during an active outbreak. Avoiding oral sex is also recommended during oral-genital contact, as HSV-1 can cause genital infections.
Our clinic in Tel Aviv is experienced in diagnosing and managing HSV-1 outbreaks and advising on prevention strategies, especially for travelers.
