Fever blisters, also called cold sores, are outbreaks of the herpes simplex virus, according to the National Institutes of Health. The virus can be dormant in the body for years until something, such as fever, stress, sun, hormone changes or another illness, activates it, causing a fever blister/blisters to form. At first, the patient feels burning, tingling or tenderness in the affected area, then blisters form and crust over. The blisters can last as long as six weeks, but they normally disappear after 10 to 14 days.
Step 1
Apply an over-the-counter numbing ointment such as lidocaine or benzocaine to the sore, or docosanol cream, the only FDA-approved non-prescription ointment for oral herpes.
Step 2
Take an over-the-counter pain medication such as ibuprofen, aspirin or acetaminophen. Follow the package directions exactly.
Step 3
Apply warm or cold compresses to the fever blister for pain relief.
Step 4
Avoid food and beverages that irritate the mouth, including citrus fruits and anything hot, spicy or salty.
Step 5
Contact your health care provider to see if prescription medication is appropriate for you. Oral tablets used to treat genital herpes, including acyclovir, valacyclovir and famciclovir, and prescription ointments and creams such as penciclovir and acyclovir can help to reduce the duration of the outbreak, according to the University of Maryland Medical Center.
Step 6
Wash your hands frequently to avoid spreading the virus to other parts of your body.
Tips and Warnings
- Docosanol cream may be helpful to some patients, but there is insufficient evidence regarding its effectiveness, according to the University of Maryland Medical Center. To prevent fever blisters, avoid sun exposure without wearing sunblock, get enough sleep, and avoid anything that causes stress on your body, according to the Mayo Clinic.
- Contact your health care provider if you have human immunodeficiency virus or cancer and develop a fever blister, or if you have a fever, rash, drooling or difficulty swallowing in conjunction with a fever blister, according to NIH. Cold sores are highly contagious. To prevent the virus from spreading, avoid contact with the lips of a person who has a cold sore or fever blister, and do not share lipstick, lip balm or toothbrushes, according to NIH.
Things You'll Need
- Medications, over-the-counter or prescription
- Compresses, hot or cold
