Posted on May 9, 2011, under HIV.
Blisters are small, fluid-filled bubbles that often break, becoming open sores filled with clear fluid or pus. Blisters can occur in groups in one specific area of the skin, or they can be distributed all over the skin.
Like red rashes, blistering rashes can be caused by adverse reactions to drugs. The most common causes of blistering rash in people with HIV infection, however, are two related viruses, herpes simplex and herpes zoster.
Herpes simplex infection-Infection by the herpes simplex virus is extremely common in healthy people. There are actually two different types of herpes simplex viruses: Type I and Type II. Type I most frequently causes the infection of the mouth called cold sores. Type II causes sores on the genitals and the anal region and is regarded as a sexually transmitted disease. Herpes simplex hides in nerve cells and periodically becomes active, causing recurrent blistering rashes. In people with weakened immune systems, herpes simplex can also affect skin on other parts of the body, and can even affect the internal organs.
Blood tests show that 15 percent to 50 percent of otherwise healthy people have one or both types of herpes simplex. Most of these people have either no problems or rare outbreaks; some have attacks more frequently, but these are brief, not severe, and restricted to the lips or genitals. By contrast, people with advanced HIV infection can have herpes simplex infections that cover a larger area of the skin, can be more painful, and can last longer.
Treatment with an antiviral drug called acyclovir (commercial name, Zovirax) usually controls symptoms. Acyclovir is available as pills and as ointment to be applied directly to the sores; when infection is severe, acyclovir can be taken intravenously. Treatment does not eliminate the virus. As a result, the infection can recur; recurrence can often be prevented or at least reduced in frequency by taking acyclovir pills.