Cold sores always seem to appear at the worst times—right before a work presentation, wedding or other important event. Not only are cold sores painful, but they can be embarrassing, too. You may feel like everyone is staring at the red, fluid-filled blister on your face. But there's no need to be embarrassed. We talked to Dr. Gary Sibbald, MD, a dermatologist in Mississauga, ON, about what causes cold sores, how to treat them and, most importantly, how to prevent flare-ups.

What is a cold sore?
A cold sore is a red blister that can appear on your lips, around your mouth or even on your nose, says Dr. Sibbald. The virus begins with inflammation or redness that turns into a cluster of blisters, which can be very painful. In some cases, the blisters can open up and leak fluid.

Cold sores are actually very common: The Cold Sores Guide reports that one in five Canadians suffer from a cold sore each year. In rare cases, a cold sore can develop into a secondary infection or into Erythema multiforme, an inflammatory skin reaction.

Does having a cold sore mean I have herpes?
Dr. Sibbald says there's a huge misconception that having a cold sore means you have genital herpes.

Cold sores and genital herpes are subsets of the herpes simplex virus (HSV). But a cold sore is Type 1 of the virus and genital herpes is Type 2. Cold sores can be spread through any form of contact, while genital herpes is only spread through sexual contact.

However, a cold sore on your mouth can spread to your genitals. "With oral sex you can get Type 1 in Type 2 zones and vice versa," Dr. Sibbald explains. That's why it's important to realize that an active or shedding cold sore virus is contagious, especially when the blister is leaking. The Cold Sore Guide warns that even after a cold sore has scabbed and fallen off, you can still be contagious in the weeks following as the skin continues to heal. Fortunately, Dr. Sibbald says about 75 percent of the population has been exposed to the virus but doesn't experience any symptoms.  

How do you prevent a cold sore from spreading?
For Dr. Sibbald, stopping the spread of cold sores is pretty simple. "Individuals with cold sores shouldn't go around kissing other people; they should either cover the open sore or at least avoid close personal contact," he says. The Cold Sores Guide recommends you refrain from sharing cutlery, drinks, towels or personal hygiene and beauty products like razors and lipstick.

Treatment for cold sores
There are many topical ointments you can buy to heal your cold sores. Unfortunately, Dr. Sibbald says many over-the-counter products have proven to be ineffective in treating them. He says the key is to find a product that treats not only the virus, but the inflammation that comes with the cold sore. That means you need an ointment, like Xerese, that has a steroid in it. According to the Cold Sores Guide, a cold sore takes 10 to 14 days to heal and it's best to start treating it as soon as symptoms—usually a tingling sensation around the mouth—appear.   

Triggers
Many people who have cold sores will experience a reoccurrence of the blisters, usually two to three times a year. Luckily, Dr. Sibbald says there are certain cold sore triggers you can avoid.

"The most important trigger is often sunlight," says Dr. Sibbald, noting stress and coexisting infections can also serve as triggers. It's hard to avoid stress and getting sick, but you can limit your exposure to the sun.

Obviously, in the summer months, it's hard to avoid sunlight, so Dr. Sibbald recommends you be diligent about wearing sunscreen when you're outside. He also suggests you buy a sunscreen stick or lip balm with an SPF so that your lips are protected from the sun.

We have more cold sore information, including what pocket-size remedy you should carry with you.