Herpes Simplex Virus (HSV)
The herpes simplex virus (HSV) can cause a blister(s) anywhere on the skin. It most commonly occurs around the mouth, or on the lips, nose, genitals, and buttocks.
There are two types of HSV:
- Type 1 - above the waist (fever blisters, cold sores). Type 1 is usually acquired in childhood.
- Type 2 - below the waist. Type 2 occurs when adults are exposed while having sex with an infected person.
The incubation period (time from infection to blisters) is anywhere from three to 20 days. The disease is very common and affects millions of people in the USA . Type 2 infections occur in up to 20 percent of sexually active adults.
HSV blisters can be recurrent and return periodically. Only about 10% of infected people have symptoms during the primary phase. If symptoms develop during the first episode, they are often more severe than in later eruptions. Primary symptoms last longer (two or three weeks) and are often accompanied by a fever, discomfort, and swollen lymph glands. Many patients do not know when they originally acquired the infection.
The disease may remain latent (inactive) for weeks, months or years before blisters return. During these periods, the virus hibernates in nerve tissue. When it becomes active, it travels through the nerves, producing blisters on the skin supplied by these nerves. The recurrences are unpredictable. Some things that may trigger recurrences are exposure to sunlight, colds or other viral infections, stress, skin irritation, and menstrual periods.