Anal Herpes: Symptoms, Diagnosis, and Treatment

Anal herpes is caused by the herpes simplex virus (HSV) and is usually transmitted by anal sex but, in some cases, can also be transmitted through oral sex. During an outbreak, painful blisters appear on the anus that gradually erupt into sores.

Studies have shown that most people who get HSV will not develop symptoms (or have only mild symptoms) but can still pass the virus to others without knowing it. Once you get the virus, it does not go away, but medications are available to reduce the frequency of outbreaks.

Cause

Anal herpes is caused by the herpes simplex virus (HSV). It belongs to a family of viruses known as Herpesviridae, which also includes the varicella-zoster virus (VZV) that causes chicken pox and shingles, the Epstein-Barr virus (EBV) that causes mononucleosis and some cancers, and cytomegalovirus (CMV).

Several factors differentiate HSV from other types of herpes viruses:

• There are two types: The majority of anal herpes infections are caused by herpes simplex virus type 2 (HSV-2). The other type is herpes simplex virus type 1 (HSV-1), which is mainly associated with cold sores but can also be transmitted to the anus via oral sex. HSV-1 accounts for an increasing number of cases, according to the Centers for Disease Control and Prevention (CDC).
• It is widespread: About one in 8 people in the United States between ages 14 and 49 have acquired HSV-2. The vast majority are unaware they have the virus because they are either asymptomatic (without symptoms) or subclinical (without readily observable symptoms). About three out of every five people in the United States will have HSV-1 by age 50, accounting in part for the rising number of HSV-1-associated anal and genital infections.
• It is highly transmissible: Anal herpes can be spread by direct contact with a sore but can also be passed through skin-to-skin contact with someone who has HSV-2 but no symptoms.
• It is chronic: Once you get HSV-1 or HSV-2, you will have it for a lifetime. But this doesn't mean that it will manifest with the same frequency or severity of symptoms in all people—or cause any symptoms at all.
  

Symptoms and Characteristics

Anal herpes can cause an outbreak of small, watery blisters in and around the anus that eventually erupt into painful open sores. The oozing sores will then quickly crust over and start the process of healing.

During the initial outbreak, the blisters may be preceded by flu-like symptoms, including headache, fever, muscle aches, fatigue, and swollen lymph nodes in the groin. Subsequent outbreaks tend to be far less severe than the first.

Infections with herpes viruses are lifelong. This means that once you get the virus, it never goes away. Instead, it stays in the body in a latent (dormant) form and can reactivate at any time to cause symptoms.

For those who develop symptoms, it is possible to have only one outbreak and never have another. With that said, you are more likely to have repeated episodes, called outbreaks, especially during the first year.

Even so, the frequency and severity of these outbreaks tend to wane over time.

Location

Anal herpes affects the skin and/or mucous membranes around the anus and in the rectum.

Like all herpes viruses, HSV-1 and HSV-2 persist in the body by entering nerve cells near the spinal cord. During the prolonged periods of latency, the virus will lie dormant, largely unseen by the immune system.

If and when the virus reactivates, it will snake its way through a path of nerve cells to the surface of the skin. In the skin, it starts to make and shed copies of itself, whether blisters are formed or not.

Reactivation is isolated to the site of the original infection unless the virus is passed to another part of the body.

Size

An anal herpes blister is typically small, only less than 1/8 inch (1–3 millimeters) in size. The blisters can sometimes converge into larger blisters and eventually erupt into a reddened, inflamed skin ulcer.

Appearance

The outbreak of herpes blisters typically occurs in clusters known as crops. The blisters will have a small, fluid-filled head that will pop either spontaneously or when rubbed or scratched.

The resulting skin ulcer has characteristic features, including:

• A concave (bowl-shaped) sore of uniform depth and size
• An oozing, reddened center
• A "punch-out" border with slightly raised edges
• Whitish or yellowish crusting
  

People occasionally worry that an outbreak of hemorrhoids is anal herpes. Hemorrhoids (swollen and inflamed veins in the anus and rectum) can cause anal itching and pain similar to anal herpes.

With anal herpes, there will typically be a cluster of red blisters around the anus that will break open to form painful sores. Hemorrhoids will typically cause a more generalized swelling and a pillow-like lump around the anus.

Sensation

Pain is a common feature of anal herpes. The pain stems from inflammatory damage caused to nerves as the virus reactivates, leading to nerve pain known as hyperalgesia.

The pain from anal herpes can be severe, especially during bowel movements or straining. The abrasion caused by a passing stool or wiping the anus can sometimes cause excruciating pain.

In some cases, the nerve pain will extend beyond the site of the anal sores to one or both sides of the tailbone.

Even so, not all herpes sores are painful. Some people may only experience mild burning or itching. Others may describe pins-and-needles sensations.

Timing of Outbreaks

There is often no rhyme or reason as to why HSV-2 reactivation occurs or why some people are more prone to reactivations than others. With that said, there are common triggers for herpes reactivation, including illness, stress, and fatigue. Menstruation can also trigger an outbreak.

People will sometimes mistake prodromal symptoms of anal herpes for sciatica (nerve pain that travels down the legs).

Healing Stages

The first episode of anal herpes typically occurs two to 12 days (an average of four days) after exposure to the virus. The appearance of blisters and sores can persist for around 10 to 15 days, gradually waning as the viral shedding decreases.

Once the sores are crusted over and no new blisters form, healing usually occurs within two to four weeks. Typically, the sores leave no permanent scars.

Subsequent outbreaks tend to be shorter and less severe. In these outbreaks, viral shedding may last only three days rather than weeks.

Transmission

Both HSV-1 and HSV-2 are transmitted by contact with someone in whom the virus has reactivated. With reactivation, a phenomenon called viral shedding occurs, in which infectious viral particles are literally shed from the body.

Although the greatest quantity of HSV is shed through open sores, the virus can also be shed through intact skin at the site of the original infection. In fact, most sexual transmissions of HSV-2 occur during periods of asymptomatic shedding.

While anal HSV-2 is primarily transmitted through anal sex, hand-to-anal transmission is also possible (such as by fingering the anus after touching a sore). It is also possible to auto-inoculate by touching a sore on your own body and then your own anus.

Anal HSV-1 is primarily passed through oral-anal sex (also known as "rimming").

Diagnosis

Anal herpes can be diagnosed with a physical exam, a review of your medical history, and a swab of the anal sores.

The swab can be used to undergo a nucleic acid amplification test (NAAT), the most sensitive form of testing that identifies HSV based on its genetic material. If this is not available, the swab can also be used to culture (grow) the virus in the lab to make a positive identification.

There are also blood tests that can detect immune proteins, called antibodies, that the immune system produces in response to HSV-1 or HSV-2. While the blood tests may be able to identify which type of HSV you have, they usually cannot tell you when you acquired the virus.

HSV blood testing is only recommended for people with herpes symptoms. The routine screening of HSV for asymptomatic people is not recommended. It has not been shown to change sexual behaviors or slow transmission.

Treatment

There is no cure for anal herpes. Rather, the infection is treated with antiviral drugs. The three antivirals commonly used to treat anal herpes, which can be taken with or without food, include:

• Famciclovir
• Valtrex (valacyclovir)
• Zovirax (acyclovir)

The choice, dose, and duration of treatment can vary based on whether this is your first outbreak or one after the first (called subsequent outbreaks).

People with frequent outbreaks can ask a healthcare provider about suppressive HSV therapy in which a low-dose antiviral is taken daily to reduce the frequency and severity of herpes outbreaks. This may be a good option for serodiscordant couples, meaning one partner has herpes, but the other doesn't.

Discussing Herpes With Your Partner

While it can be difficult to tell someone you have herpes, focus on educating your partner about what herpes is, how it is passed, and ways to prevent it. If needed, ask your partner to go with you to a healthcare provider to get the facts.

Having herpes does not mean you cannot have sexual relations with someone who does not have herpes. With that said, you need to take precautions and speak honestly with any sexual partner you have.

This may require you to educate your partner about:

• What herpes is
• How the virus is spread
• When the risk of transmission is high
• How the risk can be reduced

While safer sex practices are key to prevention, other preventive tools are available. This includes the daily use of antiviral drugs in people with recurrent herpes, which reduces the frequency of outbreaks by 70% to 80% and reduces the risk of transmission to sex partners.

Prevention

The consistent use of condoms is the cornerstone of STI prevention, including anal herpes. However, unlike many other STIs, condoms are less effective in preventing herpes because viral shedding can occur on parts of the body not covered by a condom. This includes the buttocks and groin.

To reduce the risk of transmission, people living with anal herpes need to employ additional prevention strategies, including:

• Reducing the number of sex partners
• Using dental dams for oral sex, including rimming
• Abstaining from sex during outbreaks (or when there are early signs of an outbreak)
• Using suppressive antiviral therapy
  

Summary

Anal herpes is a sexually transmitted infection (STI) primarily caused by the herpes simplex virus type 2 (HSV-2). Less commonly, anal herpes can be caused by herpes simplex virus type 1 (HSV-1), the type commonly associated with cold sores.

Anal herpes causes the outbreak of tiny blisters around the anus that break open to form painful ulcers. After oozing and crusting, the sores tend to heal within two to four weeks. It can be spread by direct contact with a sore but can also be passed through skin-to-skin contact with someone who has HSV-2 but no symptoms.

While there is no cure for anal herpes, outbreaks can be treated with antiviral drugs. You can also reduce the risk of transmission by using condoms and dental dams, daily antiviral drugs to suppress the virus, avoiding sex during outbreaks, and reducing your number of sex partners.