Cold Sores
(Fever Blisters)
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
Definition
Cold sores are small, painful, fluid-filled blisters, usually on the lips or gums.
Causes
Cold sores are caused by the herpes simplex 1 virus. The virus is related to, but different from, the virus that causes genital herpes. The virus invades the skin, then lies dormant for weeks or months before causing inflammation and blistering. In most cases, people contract the virus as infants or young children. The first episode of illness with herpes simplex 1 virus causes a systemic illness. The virus then lies dormant until it is reactivated. Once reactivated, it results in painful cold sores, usually located at the border of the colored part of the lip.
The virus can be spread by:
- Contact with the fluid from a cold sore of another person
- Contact with the eating utensils, razors, towels or other personal items of a person with active cold sores
- Sharing food or drink with a person with active cold sores
- Contact with the saliva, stools or urine of a person who has the herpes simplex virus
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition. Infection with the virus that causes cold sores is so common that everyone is considered at risk.
Once the herpes simplex 1 virus is present in the body, the following risk factors can trigger cold sores to form:
- Infection, fever, cold, or other illness
- Exposure to sun
- Physical or emotional stress
- Certain foods or drugs
- Weakened immune system
- Menstruation
- Eczema
Cold sores often form without an identifiable trigger.
Symptoms
The first episode of herpes simplex 1 infection may result in 3 to 14 days of:
- Swollen, sore throat
- Mouth sores
- Fever
- Decreased energy
- Aches and pains
- Difficulty eating
- Swollen glands in the neck
After this initial illness has passed, the virus lies dormant until reactivated. In the day just prior to a cold sore appearing, you may notice some itching, burning, or pain in the area where the cold sore will appear.
Symptoms of cold sores on the lips, mouth or skin include:
- Small, painful, fluid-filled, red-rimmed blisters
- Pain, tingling or itching for a day or two before the blister appears
- After a few days, drying of the blister, which then forms a yellow crust and shallow ulcers
Diagnosis
The doctor will ask about your symptoms and medical history, and examine the blisters. Usually, the doctor can easily diagnose a cold sore by looking at it. Cold sores have a relatively classic appearance. In rare cases, the doctor may need to take a piece of a blister to analyze it or take a blood sample for testing.
Treatment
Cold sores will usually heal within 7-20 days. Treatments for blisters on the lips, mouth, or skin include:
- Putting ice on blisters to lessen pain and promote healing
- Not rubbing or scratching blisters
- Non-prescription pain relief drugs to lessen pain and discomfort
- Non-prescription cold sore/fever blister cremes and ointments to lessen pain
- Antibiotic drugs if the blister becomes infected by bacteria
- Antiviral creme or ointment if you suffer from frequent herpes simplex 1 virus outbreaks
- Oral antiviral medications, such as Zovirax® (acyclovir) or Denavir® (penciclovir), may be given the moment you feel a cold sore coming on. These medications can decrease discomfort, and help cold sores go away much more quickly.
Prevention
To prevent the spread of the herpes simplex 1 virus:
- Avoid skin contact, kissing or sharing food, drink or personal items with people with active cold sores.
- If you have an active cold sore, avoid touching the infected area (to avoid spreading the virus to other people and/or other parts of your body).
To prevent recurring outbreaks of cold sores or blisters:
- Avoid long periods of time in the sun.
- Use sun block on lips and face when in the sun.
Organizations
International Herpes Alliance
http://www.herpesalliance.org/
American Social Health Association
http://www.ashastd.org
SOURCES:
The Merck Manual of Medical Information. Simon and Schuster, Inc., 2000.
American Academy of Dermatology
Mayo Foundation for Medical Education and Research
Last reviewed June 2001 by Medical Review Board
