Step 1: Clean the sore
Before you apply makeup to an open sore, wash the area thoroughly. Use a warm wash cloth to wipe the area clean with soap and water.
Step 2: Move to treatment
The second step is to apply a cream to heal the sore (Orajel is a good option). Use your pinky finger to dab the cream onto the affected area. Not only will this help speed up healing, it will dull any pain it may be causing.
Step 3: Get concealing
First, treat the area around the cold sore before you cover it up. Then, once you've blended your foundation into the area around the sore, take a small Q-tip or makeup brush and apply a small amount to the sore itself (you'll have to thoroughly disinfect any tools you use that aren't disposable).
From there, grab a concealer. The concealer should be the same shade as your skin and shouldn't be too thick. Apply a small amount of the concealer to the sore itself (don't cake it on—this will only draw attention to the area, especially if the sore is starting to dry out).
If you're looking for a little extra coverage, feel free to finish with a dab of powder (this helps set the makeup you've already applied so it will last longer).
You may also want to consider coloring your lips with a bold shade of lipstick (one that will draw attention to your lips instead of the cold sore). Redirecting people's eyes from your lips to another part of your face with bold eye or cheek makeup will also work.
Step 4: Be sure to disinfect
Because you've been touching the cold sore, it's important to disinfect any tools you use, including your hands, thoroughly. Cold sores are incredibly contagious. If possible, use disposable items whenever possible. And, once all of your makeup has been applied, avoid touching the region for the duration of your day or night. If your makeup begins to wear off, start the application process over again.
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