What triggers cold sore (fever blister) breakouts?
How common is it that a person has been exposed to the herpes simplex virus (HSV1)?
It has been estimated that up to 80% of the general population has the presence of herpes simplex virus antibodies in their blood. Finding these antibodies is proof positive that a person has been exposed to the virus because our immune system only creates them in response to the physical presence of virus particles within our bodies.
Herpes is forever...
After a person's initial herpes simplex virus infection (either subclinical or full-blown) some of the herpes virus particles will remain in the person's system, and remain there forever. For the most part these virus particles will lie dormant in the person's system but at times they can become active. When this activation occurs the person will experience the outbreak of a cold sore.
The good news, at least from a statistical standpoint, is that although about 80% of the general population has been infected with the herpes simplex virus (HSV1) it's in only about one third of these people that the residual virus particles will become active at times and cause recurrent outbreaks of cold sores (fever blisters). The rest of us do still carry the virus but, for whatever reasons, it remains dormant and we remain cold sore free.
Where in our bodies do the dormant herpes virus particles reside?
As we mentioned previously, it is the reactivation of dormant herpes simplex virus particles that is the cause of cold sores. Between episodes of cold sore breakouts the dormant virus particles lie quietly "asleep" in nerve tissue. (In the case of HSV1 these dormant virus particles usually reside in the trigeminal nerve ganglion.) Once reactivated the virus particles travel down the nerve to the area of the face where the cold sore lesion ultimately forms.
In most cases a person's cold sores will always recur in essentially the same general facial area. This is because this is the region that is serviced by the nerve that harbors the dormant virus particles.
What triggers the reactivation of the herpes virus?
(What triggers outbreaks of cold sores?)
Each of the following items has been found to be an event that is often associated with the formation of cold sores. Many of these factors seem to correlate with time periods when a person's immune system would be expected to be weakened or stressed. If compromised, a person's immune system, which under normal circumstances would be able to keep the herpes virus particles in check, can be overwhelmed and a window of opportunity for cold sore formation can be opened.
- Emotional upset and stress.
- Physical stress and fatigue.
- Illnesses (including a cold or the flu).
- Injury to the lips or skin, such as physical trauma or severe chapping.
- Injury to the lips from excessive exposure to bright sunlight or ultraviolet lamps.
- Menstruation or pregnancy.
- An immune system deficiency.
Research has shown that today's antiviral medications for cold sores can significantly minimize cold sore severity and duration if their use is started early enough. By observing which factors typically trigger their cold sores a person can learn when to expect an outbreak. If a person begins the use of antiviral medications early enough (preferably during the Tingle stage) they can quite possibly reduce cold sore symptoms dramatically.
