Does Kissing Spread Cold Sores?

What are cold sores?

A cold sore (sometimes called a fever blister) is a small, fluid-filled blister that usually pops up on your vermilion border (the border between your lip and your skin). You know it's a cold sore, not a canker sore or a pimple, by the itching and burning sensations that usually accompany them. 

And yes, a cold sore is a common form of the herpes virus — herpes simplex 1, to be specific. About half of all Americans¹ are infected with this virus by the time they are 49. What are the signs and symptoms?

Aside from the blister itself and the uncomfortable tingling, these are the signs that you may have caught the virus: 

• Headache (typically in the first episode)

• Fever (typically in the first episode)

• Oral ulcer

• Tingling sensation

Symptoms usually last 6–48 hours, and lesions crust and heal in about ten days.

Are cold sores contagious?

Like any virus, the HSV-1 virus is contagious. It spreads when a previously uninfected person comes into contact with herpetic lesions, mucosal secretions, or skin that has HSV-1. In the same context, transmission can occur even if the patient is asymptomatic and without lesions. 

Ultimately, HSV-1 transmission is usually oral-oral, oral-genital, or genital-genital. Unlike some viruses, once you've been exposed to the herpes virus, it lives in your body forever. 

Kissing and cold sores

If you have an active cold sore, it's best to avoid kissing anyone, anywhere, until it has completely healed. Even if the blister has dried up and is healing, you still have the live virus on your face.

Can cold sores be spread by kissing?

Yes, the virus will spread by kissing. Any skin-to-skin contact can cause the virus to hop to another person. 

How long are cold sores contagious after healing?

Once the sore has completely healed, and new skin has grown over the area, your chances of spreading the virus decrease drastically. However, HSV-1 can also be shed asymptomatically in up to 25%² patients.

How long are cold sores contagious on surfaces?

The HSV-1 virus only lives about four hours on plastic surfaces. If you have a cold sore, don't touch it. Washing your hands with warm soapy water and drying them on a clean towel helps stop the spread of the virus. Do not spit on your contact lenses.

Can I get a cold sore by borrowing beauty products?

If you have a cold sore, the virus is likely to shed on any makeup products you use on your face. The virus survives better in high humidity, so if you keep your makeup and brushes in the bathroom, they live longer. 

The six stages of a cold sore

Every cold sore goes through six stages of development. The virus is active during each of these stages.

• Latent

This is when the virus is dormant in your body. You won't have any symptoms and may even forget you have the HSV-1 virus. During the latent phase, no infectious virions are produced.

There is periodic reactivation (lytic replication), which can be asymptomatic or symptomatic. 

During symptomatic reactivation:

• Prodromal

You may notice tightness and tingling in the area where the virus is replicating and about to develop. If you know the signs of an outbreak, this is when you should start treatment. You are contagious at this point. 

• Vesicular Lesion

In about 6–48 hours, a vesicular lesion will develop. Typically there’s only a single lesion and no systemic manifestations. However, this can be so uncomfortable that eating, drinking, and talking are painful.

•  Ulceration

When this happens, the lesion opens up and oozes fluid from the exposed sore. This is the most infectious stage of the sore.

• Crusting over

By now, your body's immune system is fighting the virus back. The crust ultimately becomes a scab. You're still shedding the virus, even though the blisters are covered. 

• Healing

The scab has grown to obscure the sore, and new skin is growing underneath. Then it's back to the latent stage. The whole reactivation typically takes about ten days to crust and heal.

The best way to protect your family when you're having an outbreak is to keep your hands super clean and not share anything — in this case, not sharing is caring. 

Speeding up the cold sore healing process

You can heal faster by recognizing the signs of an impending outbreak and starting treatment as soon as you have tenderness and itching. Over-the-counter medications like Abreva cream or a Compeed patch are options. However, topical therapy for cold sores is typically not recommended, and oral therapy is preferred. 

When should you see a doctor?

See your doctor if you have a recurrence or initial infection with HSV-1. They can diagnose any underlying conditions, guide on triggers, and prescribe antiviral medication to treat HSV-1.

The lowdown 

There's no reason to panic if you have a cold sore, but you should keep your affection limited to hugs during an outbreak. Try not to be embarrassed. But if the sore makes you socially anxious, the Compeed patch does a good job of hiding it. If you've kissed someone contagious, you may want to discuss your options with your physician concerning antivirals.