Alternate Names : COLD Sores
Fever blisters are small sores in the mouth or the area around it. They usually develop on the gums, roof of the mouth, outside of the lips, or the nostrils.
What is going on in the body?
Fever blisters are caused by the two types of herpes simplex virus. Most fever blisters are caused by herpes simplex virus 1, or HSV 1, which causes oral herpes. The virus that causes genital herpes, HSV 2, may also cause fever blisters.
The two stages of oral herpes are primary infection and recurrence
of infection. At some time during childhood, most people come down with the
primary infection. The individual may or may not have symptoms. This primary infection takes
about 2 weeks to clear up. After that, the virus remains in the body but is inactive.
After this primary infection, there can be a recurrence at any time. Many outbreaks occur without any obvious reason. However, the following factors may trigger a recurrence:
exposure to sunlight
an upper respiratory infection, such as a cold or flu
What are the causes and risks of the condition?
Fever blisters are caused by a herpes virus. People in the following categories may be more at risk for oral herpes:
people undergoing radiation therapy or chemotherapy
people with cancer or other debilitating diseases
people with HIV or other immunodeficiency disorders