/ Cold Sores
How Long Are Cold Sores Contagious?

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What Is A Cold Sore?

Cold sores are caused by a viral infection called herpes simplex virus (HSV-1) that is very common. These tiny blisters are filled with fluid and often appear in clusters on or around your lips. They can also appear as a single sore filled with clear fluid. When the blister breaks open, a crust forms and then starts to scab.

How Long Does A Cold Sore Last?

Generally, the initial outbreak from a cold sore can last for 10 to 12 days, sometimes up to two weeks. Over time, subsequent outbreaks usually lessen in severity and take less time to heal. There are five stages in the development of a cold sore:

Day 1-2: Tingle Stage – Tingling and itching may occur for 24-48 hours. Treating a cold sore early in this stage can help reduce the time it takes to heal.

Day 2-4: Blister Stage – A sore or cluster of tiny sores that look like blisters will appear and begin to fill with clear fluid. The skin may be red underneath and surrounding the blisters.

Day 4-5: Ulcer Stage – At this stage, the blister will burst open and begin to ooze. The sores are probably painful and itchy. The cold sore may look red and shallow.

Day 6-9: Scabbing Stage – The blistery sores will begin to dry out and scab over. They may crack and itch. As the blister dries out, it will turn a brown or yellowish color.

Day 10-12: Healing Stage – Finally, the scab will start to fall off or flake away and begin to heal. It doesn’t usually leave a scar.

How Long Are Cold Sores Contagious?

By the time you start to feel the tingling of the cold sore underneath your skin, the very contagious HSV-1 virus has already started to rear its ugly head and it will be possible for you to spread it to others. The most contagious times for a cold sore are when the blisters begin to show up and after they burst, releasing their clear fluid.

When your skin has healed from the cold sore and looks normal, you will not be able to spread the virus from the cold sore. However, because the herpes virus stays dormant in your body, you can still pass on the virus through your saliva, even if you don’t have a cold sore.

Once you catch the HSV-1 virus, you will have it for life. For some people, the virus lies dormant and they never have symptoms. Most others get breakouts of cold sores.

Its common to think that a cold sore isn’t contagious any more once it has scabbed, but this isn’t the case. You are still contagious until the cold sore completely heals. Cold sores can be spread through skin-to-skin contact like kissing, oral sex, or sharing objects such as towels, eating utensils and straws. The virus is contracted through any break in your skin that may not even be noticeable to you.

Is There Medication for Cold Sores?

Although there is no cure for cold sores caused by the HSV-1 virus, you can help speed up the healing process by taking medication in the earliest stages of your symptoms, such as when you start to feel the tingly, itchy red skin. Prescription medications like acyclovir can be taken before a flare up to prevent it from getting to a full blown cold sore.

Have cold sores? Book an appointment with a PlushCare physician and get a prescription treatment sent to your pharmacy today!

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Margaret A Spera, NP, APRN

Margaret A Spera, NP, APRN

Margaret Spera is a Connecticut-based nurse practitioner. She has worked in hospital settings, family practices and senior care facilities for over 40 years.

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