Cold sores, also referred to as fever blisters, are caused by two strains of the herpes simplex virus, HSV-1 and HSV-2. Both types cause an infection that results in painful blisters.The wounds typically show up on the rim of your mouth or on your lip, cheeks, fingers and nose but are not restricted to these areas. People who have the virus can spread to another person. The greatest chance of spreading the disease is when the sores are oozing. Cold sores can be spread by sharing razors and towels, eating from the same utensils, kissing and oral sex.

How Long Are Cold Sores Contagious?

Cold sores are contagious for 7-10 days in the whole healing process. When a cold sore appears, it looks like a small raised bump. Shortly after the blister forms, it will break and ooze. A yellow-crusted scab develops and covers it but will eventually come off itself. The wound will clear completely in a week to 10 days. It used to be commonly believed that cold sores were no longer contagious once they scabbed over. This is untrue. When a blister is in the healing process, it can scab and slough off many times before it completely heals. It is contagious the whole time when it exists. It can be spread from the moment the blister starts.

Cold sores are caused by the herpes simplex virus, so they cannot be cured. Even when you are not experiencing an outbreak, the illness is always in your body. Because of this, you can spread it at any time but chances are greater when blisters can be seen.

Who Are at Higher Risk of Cold Sores?

So now that your know “how long are cold sores contagious”, it is important to know who have a higher risk it of suffering from them.

• People who suffer from high levels of stress or are fatigued.
• People who have food allergies.
• People who are exposed to the sun, which will increase development of cold sores on lips.
• People with a weak immune system, which may cause them to have more or longer outbreaks and possibly face life-threatening symptoms.
• People who have cosmetic procedures, like laser and dermabrasion treatments.
• People who have injured their gums or lips or have undergone dental surgery or treatments.
• People who are going through hormone changes, such as women who are menstruating or pregnant.
• People who have the flu or a cold.

How to Tell If You Are Infected with Cold Sores

When you first contact the herpes simplex virus, you may not have any recognizable symptoms. This is called the primary infection. Some people may feel mildly sick or under the weather, but this usually happens to young children under 5 years old. The symptoms of primary infection include:

• ŸBlisters on the inside of your mouth.
• ŸBlisters on the rim of your lips or nearby.
• ŸSwollen glands.
• ŸSore throat and swollen areas near your neck.
• ŸIncreased saliva output.
• ŸBad breath.
• ŸBeing thirsty and dehydrated.
• ŸFeeling sick and experiencing headaches or fever.

With the primary infection, kids are more likely to form cold sores in their mouths and experience swollen gums, both of which are painful. The blisters will make it difficult to drink and eat, and can last up to two weeks.

As an adult if you experience symptom during your primary infection, they will most likely appear as swollen tonsils, a sore throat or a fever related illness.

Once you go through this stage of the illness, the virus is dormant in your system. When it becomes active, you will experience cold sores.

Symptoms of cold sores include:

• ŸRedness, swelling and a tingling sensation around the area the cold sore forms.
• ŸA blister which is filled with fluid that breaks open and forms a yellow-crusted scab. The scab sloughs off in about a week to 10 days.
• ŸColds sores that reoccur typically at or around the same spot.

When to See a Doctor

Now that you have learned about “how long are cold sores contagious”, you need to know when you need to see a doctor. Most people who have blisters caused by HSV-1 type do not see a doctor. But if you suffer from a weak immune system because of medical treatment and illness like HIV or cancer, you may need to seek your physician’s advice. Also, if you experience frequent recurrences, have blisters that last over two weeks or the condition is affecting your eyes, you should seek medical care as soon as possible. You may be suffering from another illness that is causing the cold sores to develop.

How to Prevent Spreading Cold Sores

Ways to prevent spreading cold sores to others include:

1. Stop Sharing

It sounds mean but cold sores are easily spread by sharing things that go in or near your mouth. This includes drinking straws, eating utensils, glasses, chopsticks, toothbrushes, lip stick, razors, lipstick and lip liner. You can even pass by sharing a towel you dry your face with because the herpes simplex virus can survive for a short time on non-living belongings or surfaces.

2. No Kissing

When blisters and cold sores are present, avoid kissing. This includes anywhere on the body, but especially around the mouth and lips. 

3. Avoid Touching

Illnesses are spread all the time by touching our faces after the contact with germs. When you touch your cold sores, you get the virus on your fingers and the next thing you touch can be used as a conduit for spreading the infection. Always wash your hands and frequently use hand sanitizer.

4. Wash with Hot Water

Anything you use such as dishes, sheets and towels should be washed with hot water. By doing so, you will kill the virus left on the items.

5. Keep Away from Triggers

When you are experiencing a cold sore blister you are most likely to spread the virus. Stay away from the things that make them appear, such as too much sun and excess stress. Try to eat healthy and get enough sleep.

6. No Oral Sex

The two types of herpes simplex viruses can be spread from one area to another. So if you have a cold sore and then engage in oral sex, you can spread the blisters to your couple’s genital area.

How to Treat Cold Sores If You Get Infected

Apart from the knowledge of “how long are cold sores contagious”, you may also need the remedies to treat cold cores in case you are infected.

1. Home Remedy

There are several things you can do at home to ease your cold sore symptoms:

• Use a cool compress on the area of the blister to reduce inflammation and help the healing process.
• Apply an over-the-counter cold sore ointment, such as Abreva, to potentially shorten the blister outbreak.
• Try pain-relieving creams like benzocaine or lidocaine for pain relief.
• Use over-the-counter cold sore remedies designed to be a drying agent to speed the healing process.
• Apply moisturizing lip balm containing sunblock to keep your mouth and lips from becoming too dry.

2. Medicines

While cold sores usually clear up on their own, there are antiviral medications available through prescription that might shorten the outbreak. Some are in oral pill form, while others are creams. Pills tend to be more effective, but in the case of a severe virus infection, they may need to be administered by injection.

Medications include:

• Penciclovir (Denavir)
• Valacyclovir (Valtrex)
• Acyclovir (Xerese, Zovirax)
• Famciclovir (Famvir)