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Cold sores (herpes simplex type 1)
Cold sores (also called fever blisters) are cause by herpes simplex virus. There are two types of herpes simplex virus, type 1 and type 2 (HSV1 and HSV2). Cold sores are usually caused by type 1 while type 2 is more often associated with genital herpes.
How herpes simplex is spread
The virus is spread by skin or mucous membrane (the thin moist lining of many parts of the body such as the nose, mouth, throat and genitals) contact with infected saliva. People with a history of cold sores may shed the virus in their saliva even without a blister being present. Sometimes these viruses can cause infections of the eyes, hands or brain, and may cause severe illness in pregnant women or people whose immune systems are weakened.
What Are Oral Herpes (HSV-1, Herpes Simplex Virus-1) Symptoms and Signs?
- ncubation period: For HSV-1, the amount of time between contact with the virus and the appearance of symptoms, the incubation period, is two to 12 days. Most people average about three to six days.
- Duration of illness: Signs and symptoms will last two to three weeks (healing time). Fever, tiredness, muscle aches, and irritability may occur.
- Pain, sore lips, burning sensation, tingling, or itching occurs at the infection site before the sores appear. These are the early symptoms (prodrome). Sometimes these symptoms happen prior to the appearance of sores, bumps, pimple-like lesions, or blisters (herpes or herpetic stomatitis). Thereafter, clusters or groups of painful blisters (also termed fever blisters) or vesicles erupt or ooze with a clear to yellowish fluid that may develop into a yellowish crust. These blisters break down rapidly and appear as tiny, shallow gray ulcers on a red base. Fever blisters are smaller than canker sores. A few days later, they become crusted or scabbed and appear drier and more yellow.
- Oral sores: The most intense pain caused by these sores occurs at the onset and can make eating and drinking difficult.
- The sores can occur on the lips, gums, throat (causing a sore throat), the front of or under the tongue, the inside of the cheeks, and the roof of the mouth.
- They can also extend down the chin and neck.
- The gums can become mildly swollen, red-colored, and may bleed.
- Neck lymph nodes often swell and become painful.
- People in their teens and 20s can develop a painful throat with shallow ulcers and a grayish coating on the tonsils
Incubation period
(time between becoming infected and developing symptoms)
2 to 12 days.
Infectious period
(time during which an infected person can infect others)
Spread of infection is most likely when a moist blister is present. However, people with a history of cold sores may shed the virus in their saliva and are therefore capable of infecting others even without a blister being present.
How Are Cold Sores Diagnosed and Treated?
Cold sores normally go away on their own within 7 to 10 days. Although no medicines can make the infection go away, special prescription medicines and creams can shorten the length of an outbreak and make the cold sore less painful.
If you have a cold sore, it’s important to see your doctor if:
- you have another health condition that has weakened your immune system
- the sores don’t heal by themselves within 7 to 10 days
- you get cold sores often
- you have signs of a bacterial infection, such as fever, pus, or spreading redness
To make yourself more comfortable when you have a cold sore, you can apply an ice pack wrapped in a towel or anything cool to the area. You also can take an over-the-counter pain reliever, such as acetaminophen or ibuprofen.
