Fever Blisters and Cold Sores


The herpes simplex virus type 1 (HSV-1) cause fever blisters and cold sores. The virus can be transmitted to others through the saliva or contact with the infected skin. Cold sores have the appearance of multiple clusters of miniature blisters on the lip(s). Most individuals are infected by HSV-1 prior to the age of 10 y.o. Following this initial infection, the HSV-1 virus remains dormant in the facial nerves. The HSV-1 virus becomes active in some individuals time and again. This is what causes cold sores and fever blisters to appear on the lip(s). They are called cold sores and fever blisters, because they usually become active when one has a cold or a fever.

Mental, emotional, and physical stresses can also cause an outbreak of cold sores or fever blisters. By physical stresses we mean, routine dental treatment, illness, lip trauma, or exposure to the sun. The eyes, genitals, and the skin of the fingers, can also become infected with HSV-1. HSV-1 can also cause other serious medical problems in individuals with reduce immune defences. HSV-2 is the virus that usually causes genital herpes.


An HSV-1 infection during its initial infection stage can cause headaches, fevers, nausea, vomiting, and painful open sores in the mouth (usually lasting for approximately a week). Then, when HSV-1 is reactivated later in life, they usually show up as a fever blister of cold sore. Fever blisters and cold sores usually occur following an illness, poor nutrition, stress, exposure to sunlight, or for no reason at all. Dental treatment where your lip is manipulated or stretched can also cause a fever blister or cold sore breakout.

Fever blisters and cold sores usually occur on the border of the lip, but can also occur inside the mouth. Cold sores that occur inside the mouth may also be indicative of immune weakness or a medical condition. The initial signs of a breakout are tingling, itching and/or burning, and then swelling and redness. Then, 24-48 hrs later, miniature fever blisters occur, which then cause more painful cold sores that are eventually covered by crusts. These crusts then shed and will reform while the cold sore is healing.


When visiting your dentist or doctor, cold sores can usually be diagnosed from examining you and from your medical history. Other tests are occasionally performed by your doctor to diagnose cold sores; however these tests are not necessary in healthy individuals.


When first infected, symptoms can last 7-14 days, crust by 4 days, and completely heal in 8-10 days.


Do not allow children to be kissed by anyone that has their first signs of HSV-1 infection, fever blister, or cold sores to try to prevent an initial infection. However, HSV-1 is very common and most children will become infected by adulthood. Vaccines are available for HSV-1 and HSV-2, but these only work in individuals that have not been infected. Evidence suggests that sunscreen may help to prevent cold sores. There are also several antiviral medicines that can help prevent cold sores in certain situations.


Several medications are available to help augment cold sore healing, and relieve the discomfort and pain of cold sores. These medications include acyclovir (Zovirax), valacyclovir (Valtrex), and famciclovir (Famvir). These medications do not eliminate the virus, but you should take them when you have the earliest signs and symptoms of a cold sore. Once there are blisters present on your lips, you cannot do much to help. Some people even take these medications when they have stress, to help prevent the cold sores. So, if you do have a fever blister or cold sore, keep the area very clean, apply lip balm, and don�t kiss anyone.

Professional Help:

Fever blister or cold sores are common and are not usually harmful. However, if you do have a lowering of immune system defences, HSV-1 can cause more serious health problems. Make sure that you contact your dentist or physician if the fever blister or cold sore last for more than a week has difficulty swallowing or talking, develop temperature, or if additional outbreaks occur immediately.


These are lifelong problem