Oral lesions (mouth
sores) make it painful to eat and talk. Two of the most common recurrent oral
lesions are fever blisters (also known as cold sores) and canker sores. Though
similar, fever blisters and canker sores have important differences.
What are fever blisters?
Fever blisters are
fluid-filled blisters that commonly occur on the lips. They also can occur on
the gums and roof of the mouth (hard palate), but this is rare. Fever blisters
are usually painful; pain may precede the appearance of the lesion by a few
days. The blisters rupture within hours, then crust over. They last about seven
to ten days.
Why do fever blisters reoccur?
Fever blisters result
from a herpes simplex virus that becomes active. This virus is latent (dormant)
in afflicted people, but can be activated by conditions such as stress, fever,
trauma, hormonal changes, and exposure to sunlight. When lesions reappear, they
tend to form in the same location.
Are fever blisters contagious?
Yes, the time from
blister rupture until the sore is completely healed is the time of greatest
risk for spread of infection. The virus can spread to the afflicted person’s
eyes and genitalia, as well as to other people.
How are fever blisters treated?
Treatment consists of
coating the lesions with a protective barrier ointment containing an antiviral
agent, for example 5% acyclovir ointment. While there is no cure now,
scientists are trying to develop one, so hopefully fever blisters will be a
curable disorder in the future.
Tips to prevent spreading fever blisters
• Avoid mucous
membrane contact when a lesion is present.
• Do not squeeze,
pinch, or pick the blisters.
• Wash hands carefully
before touching eyes, genital area, or another person.
Note: Despite all
caution, it is possible to transmit herpes virus even when no blisters are
present.
