Cold Sores Patient Guide
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Developed by the dermatologists of Skin Care Guide

Cold Sore: Frequently Asked Questions

Cold sores FAQ
Who gets cold sores?
Anyone who is infected with the HSV-1 (Herpes Simplex) virus can get cold sores. Less commonly, those with a HSV-2 infection, which is more known for causing genital herpes, can cause cold sores in adults. Between 20 to 40% of people are thought to be susceptible to recurrent outbreaks while others may be carriers of the virus but not show outward symptoms.
How do you prevent cold sores?
HSV-1 is an extremely common virus, and can be passed by sharing cutlery, cups, and towels, so many are infected by their parents early in life. If you are having an outbreak of cold sores, as a parent you should do your best to minimize the chance of passing it to your children by minimizing direct contact when you show symptoms, but perfect prevention is often not feasible.

In terms of preventing or minimizing outbreaks (if you have the virus), treat your body well by getting plenty of rest, eating healthy, and avoid common triggers like stress, fatigue, and food allergies. Use lip balm, preferably with SPF as sun exposure can sometimes trigger cold sore outbreaks. During an outbreak, avoid eating citruses as these can be painful on the sores and temporarily worsen the symptoms.
Why won’t the immune system just kill the herpes virus?
The healthy immune system typically controls the herpes virus within a week or two during an outbreak when the virus becomes active and proliferates. During its dormant stage, when the virus retreats to the nerves where the immune system cannot reach it.
What factors trigger outbreaks?
The exact triggers are difficult to identify, and there is a lot of variation among individuals. There is definitely a genetic factor at play when it comes to susceptibility to the virus, but in terms of environmental factors, the most important factors appear to be immune health, and stress. These factors appear to trigger outbreaks in many people:
  • Fever or illness
  • Menstruation or other hormonal changes
  • Infections
  • Diabetes, hyperthyroidism
  • Fatigue, lack of sleep
  • UV exposure
  • Windburn
  • Dry lips
  • Dental treatment
  • Allergic reactions, especially foods
  • Physical injuries
We can’t cure the virus. The symptoms go away. What’s the point of treatment?
The goal of treatment of recurrent Herpes Labialis should be to reduce viral multiplication and minimize the impact of the inflammatory response on Herpes Labialis development and progression.

Most people deal with cold sores as they come. There are treatments that can significantly reduce the healing time, and total duration of the outbreak. Typically, treatments are most effective when taken early in the course of the outbreak.
What is the typical course of a cold sore outbreak?
While the triggers for an outbreak vary from person to person, the cold sore itself follows a relatively predictable course.

Prodromal Stage: People who have frequent outbreaks are often familiar with this precursor symptom before the outbreak. There may not be any visible symptoms at this stage. You could however feel some tingling, burning or itching at this stage. It usually occurs in the first 24 hours of a cold sore and many treatments are most effective when taken at this stage.

Inflammation: Virus replicate quickly in the first three days, and the cells react by causing inflammation to combat this. Blisters may begin to form in clumps and be sensitive to touch.

Open lesions: On the 4th or 5th day, the blisters may break open, creating a weeping ulcer. Fever may occur. This is often the most painful time during a cold sore outbreak, and the virus is extremely contagious at this stage.

Crusting: A crust will form that may be yellow to brown in color. This may be unsightly but an important part of the healing process, and may last until 7 or 8 days in.

Healing: A scab forms as new skin begins to form underneath. Although the virus is retreating back to its latent stage, the area may still itch, and be irritating.
Does poor hygiene cause cold sores?
Absolutely not. Cold sores are the result of a viral infection—one that is so prevalent that nearly half of the population has it. Cold sores may seem less prevalent than this, only because many people do not show recurrent symptoms as their immune system controls the virus more efficiently.
Can I avoid contracting cold sores by simply avoiding anyone that is showing cold sores symptoms?
Unfortunately, you can’t completely avoid the risk of getting an HSV infection. Although the viral load is highest when the cold sores are visible, the virus may be present in sufficient numbers to transmit the virus via contact even when there aren’t any visible symptoms.
Every time I go to the dentist, cold sores seem to pop up. Am I getting a viral infection there?
Unfortunately this is a very common cause of cold sore recurrence, but the dentist isn’t giving you cold sores or re-infecting you; you already have the virus. Stress from the dental procedure can temporarily weaken the immune system, making way for the virus to reactivate. If you suffer from recurrent cold sores, you may want to prepare for an outbreak by having some treatments ready in case you do develop symptoms.
What should I do if my child gets cold sores?
The most likely source of infection is through you, the parents, via sharing utensils or towels, or a kiss. Do your best to avoid these forms of contact if you have visible symptoms of a cold sore. Unfortunately, complete prevention is impossible or at least impractical as so many people have it, and it can be transmitted even if symptoms aren’t visible.
Why are cold sores so stigmatized?
A major contributing factor to the fear and stigma is that HSV is associated with an STI—genital herpes. STIs are very common and should not be stigmatized in the first place, but it's also important to remember that the HSV-1 strain, which is associated with cold sores are different from HSV-2, which is mostly associated with genital herpes.