What are cold sores?

Cold sores are a common viral infection. They are small fluid filled blisters that appear on parts of the face, usually on the lips and around the mouth. Cold sores have several typical stages of progression:

• Stage 1 -you will feel a tingling, itching or burning feeling

• Stage 2 -appearance of small fluid filled painful blister(s)

• Stage 3 -blisters grouped in patches, burst and scab over

• Stage 4 -scabs heal slowly leaving no visible scar from the cold sore

Cold sores, for most people, usually begin to heal within 10 days without treatment. For some people, it may be appropriate to seek treatment if their cold sores are bigger than normal or take longer to heal than expected.

How do you catch cold sores?

Cold sores are caused by a virus called the herpes simplex virus (HSV). This virus is very common as it is caught by coming into contact with other people with an active infection. Around 70% of American adults have oral herpes (cold sores).

For most people, the virus lies dormant in the skin, suppressed by your immune system. Occasionally the virus reactivates causing a cold sore. This is often when your immune system is temporarily weakened, by example through stress or illness.

As cold sores are caused by a viral infection and there is currently no cure, many people will experience repeated cold sores. This is because the virus repeats the cycle of reactivation over and over again.

When are cold sores contagious?

Cold sores are contagious from the time you feel a tingling, itching or burning sensation on your mouth or face to when the blisters burst, scabbed over and are invisible.

Whilst you have cold sores, avoid sharing eating utensils, drinking bottles or other items that regularly come into contact with your mouth and face. Also, avoid touching the cold sore directly and wash your hands regularly to help prevent the virus from passing from one person to another.

Cold sores and genital herpes

There are two types of herpes virus. Cold sores are typically caused by type 1 virus (HSV-1). HSV-1 can cause sores on the genitals and type 2 virus (HSV-2) can cause sores on the mouth. The virus that causes cold sores can be transmitted to the genitals and anus, potentially causing genital herpes. This is not as common but if you are worried, avoid touching your cold sores, wash your hands regularly and consider treating your cold sore with antiviral medication.

While you have a cold sore, avoid oral sex as this can increase the risk of passing the virus to a partner. Also, use a condom during sex to reduce your risk of contracting or passing on HSV infection of the genitals.

When do cold sores need treatment?

Cold sores are very common and most people do not need treatment. However, if your cold sores occur frequently, are large, painful, prolonged or you are at high risk of serious complications, such as from a weakened immune system, a doctor may prescribe you with an antiviral medication such as Valtrex. To prevent the herpes virus from growing and spreading you will need to take the antiviral medication on the day you notice the cold sore forming.

What is Valacyclovir?

Valacyclovir is an antiviral drug used to treat herpes simplex virus infections that cause cold sores in adults. Valacyclovir slows the growth and spread of the herpes virus to help the body fight the symptoms of the infection. Since the virus reproduces very early in the infection, you will benefit most from treatment if you take Valacyclovir tablets as soon as the first symptoms appear. Valacyclovir, is not a cure for herpes simplex and it does not prevent you from spreading the virus to other people. People who have frequent episodes of cold sores can also take Valacyclovir to help to prevent the attacks.

What is suppression treatment?

Suppression treatment may be suitable if you experience very frequent episodes of cold sores, more than six recurrences a year. Antiviral drugs taken daily for cold sores can prevent or reduce the duration of symptoms, the frequency and severity of recurrences and can reduce the likelihood of transmission to your partner. Studies show that outbreaks are milder and shorter than without suppression treatment.

How to take Valacyclovir

• The usual dose is 500 mg twice daily.
• You should take Valacyclovir for three days.

• the usual dose is one 500 mg tablet once a day
• the duration of suppression treatment is normally 3-5 days.

What is the difference between Valacyclovir and Acyclovir?

Valacyclovir and Acyclovir are closely related antiviral drugs that work by interfering with the viral DNA replication. Acyclovir is the active drug and valacyclovir is a pro-drug. This means that after valacyclovir is taken, it is converted in the body to Acyclovir.

Both drugs target the same viruses and are equally effective for treating cold sores. Valacyclovir provides a useful alternative to Acyclovir with the advantage of a simpler dosing regimen because it does not have to be taken as frequent, potentially making it more convenient to comply with. For suppression treatment Valacyclovir is deemed to be more tolerable but Acyclovir is much less expensive, making it more cost-effective.

As with all medicines, this medicine can cause side effects, although not everybody gets them. Valaciclovir should only be taken after carefully weighing the potential positives and negatives in conjunction with a qualified healthcare professional. The most common adverse reactions reported by patients treated with Valaciclovir were headache and nausea.

The following side effects have also been reported:

Common (may affect less than 1 in 10):

• Feeling sick
• Dizziness
• Vomiting
• Diarrhoea
• Skin reaction after exposure to sunlight (photosensitivity)
• Rash