Types of Herpes Blisters

There are eight herpes viruses (viral family herpesviridae) that cause disease in humans. Of these, three commonly cause rash with blisters in a total of four different conditions. These rashes share common appearances but are accompanied by different symptoms and have varying levels of severity and infectiousness.

Commonalities

• The herpesviruses that lead to rashes with blisters are the type that become latent after initial infection in nerve cells. Other herpesviruses go latent in immune cells and do not lead to blisters; however, two others, human herpesvirus-6 (HHV-6) and HHV-7, cause a childhood illness known as roseola, which leads to rash without blisters.

  All three of these viruses respond to treatment with the same group of antiviral drugs. These include acyclovir, valacyclovir and famciclovir. All herpesviruses can also lead to more serious infections in people with weakened immune systems, as in the case of advanced HIV-disease.

Oral Herpes

• Oral herpes, also known as cold sores, is caused by the human herpesvirus-1 (HHV-1, also known as HSV-1) and sometimes by HHV-2, which causes genital herpes. It causes fluid-filled blisters atop a red rash; throughout the course of the outbreak, these break and then crust over; blisters generally occur on the face but can sometimes occur inside the mouth, making it important to distinguish a possible oral herpes infection from canker sores.

  Before an outbreak, people with oral herpes experience prodrome, which consists of a burning, tingling or itching feeling in the place where the cold sore will appear.

  Cold sores are most infectious when they are active. However, according to the Mayo Clinic, it is still possible to spread the virus even when there is no active outbreak, either through close contact with the skin or by sharing things like drinking glasses and towels.

Genital Herpes

• Most cases of genital herpes are caused by HHV-2, although some can be triggered by HHV-1. As in oral herpes, prodrome is experienced by genital-herpes sufferers, followed by a red rash and fluid-filled blisters that eventually crust over. HHV-2 is most infectious during an outbreak but can be spread through contact with skin or through the use of shared items in the absence of an outbreak.

  People who experience chronic outbreaks of genital herpes may be prescribed daily suppressive therapy, a daily course of antiviral drugs that decreases the number of outbreaks in addition to reducing one's chances of spreading the virus to others. Sexual contact should be avoided during an outbreak. Although the use of condoms and dental dams is advised to reduce the chances of transmitting the virus to others, genital herpes can still be spread through skin that is not covered by barriers.

Chickenpox

• Chickenpox is caused by varicella-zoster virus (VZV, HHV-3). Chickenpox is a common childhood disease, although VZV can be contracted at any time in a person's life if she has not already had chickenpox. Chickenpox, like oral and genital herpes, leads to a red rash with fluid-filled blisters that crust over. However, chickenpox rash and blisters can appear all over the body, while oral and genital herpes rashes are localized. Chickenpox is infectious through direct contact with the rash as well through coughing and sneezing, according to the Mayo Clinic.

Shingles

• Shingles, also known as herpes zoster, is also caused by VZV. After chickenpox symptoms clear, VZV becomes latent in a nerve cell and generally does not cause any more symptoms for years or even decades. When the virus becomes active again, it causes pain that can be quite severe as well as a rash and fluid-filled blisters. However, unlike chickenpox, the rash and pain associated with shingles occur only along the path of the nerve in which the virus was latent. This is generally found on the buttocks or on the trunk of the body, although other areas of the body, including the face can be affected.