Oozy, painful and swollen, cold sores are caused by a very common infection - that of the Herpes Simplex I virus. So what should you do when they appear? This guide will offer you useful pointers to treat and prevent them. 

Is this a cold sore?

Cold sores commonly appear around the edges of the mouth. The first signs are usually itching and an irritated patch of skin. Then, you will notice a small cluster made of tiny fluid-filled blisters on the same spot. These will ooze a clear liquid that can crust a bit. Sometimes, you may also develop a fever, swollen lymph nodes, and headaches. The delicate skin inside your mouth may also feel painful (1). If you are prone to acne, you may confuse cold sores with a common pimple close to your lips. However, pimples will consist of just one, visible white head (the one that everyone says you shouldn’t pop).

Why do they appear?

Cold sores are the result of an infection by the Herpes simplex virus (HSV), which affects up to two-thirds of the world’s population. In some countries, infection rates can be as high as 90% (1,2).

The primary infection usually happens during childhood, and it usually carries no noticeable symptoms. However, it sometimes involves a very painful outbreak of oral blisters, mouth ulcers, sores and even cold-like symptoms (known as “herpetic gingivostomatitis”). Afterward, the virus can lay dormant for years, hiding deep in your nervous tissue. Cold sores are likely to “flare-up” later on due to a variety of reasons (3), such as: low immunity, sunburn, stress or hormonal changes.

How to treat cold sores?

If you are an otherwise healthy adult, there is a good chance that you won’t need much when it comes to treatment (4). Cold sores will heal on their own after a week to ten days, so simply make sure to keep the area clean and to wash your hands thoroughly after touching your sore. If they are very painful or you would like to make them disappear faster, there are some options available:

Antiviral creams

Antiviral creams and ointments, such as Acyclovir, are commonly used against newly appeared cold sores. They can keep the virus from spreading to other parts of your face and provide symptom relief if you start the application on the first day of itching. These are sometimes mixed with a corticoid cream to help lower skin irritation (5). Either way, creams will need to apply five or six times a day.

Antiviral medication

Antiviral tablets and pills can help combat the Herpes infection and may prevent its reappearance. They won’t do much to help your current cold sores heal faster: on average, they will shorten their life for about a day (6). They will also require a doctor’s prescription. This is why antiviral tablets are usually reserved for people with a weak immune system or who get very frequent or very large cold sores.

Over-the-counter remedies

Many over-the-counter creams or ointments can help you relieve some of the discomfort brought on by cold sores. This includes zinc oxide creams and moisturisers with camphor, menthol, or benzocaine (7). Keep in mind that they won’t speed up healing, and if you have any allergies, it’s best not to experiment with any unknown brands. 

Caring and Managing Cold Sores

Curing is one thing, but enduring is quite a different matter. The tips below will help you keep the infection contained until your cold sore heals. Any liquid oozing from your sores will likely be loaded with the virus and cause it to spread.

Make sure to:

- Wash your hands immediately after touching the sore

- Avoid popping the little blisters

- Disinfect the area thoroughly with soap and warm water every day

- Cover the sore with a bandaid, and replace it daily and after every shower

- Avoid sharing straws, towels, soap bars, or pillowcases with others until the sores heal 

- Avoid kissing other people

If your sore grows into an open wound, you may need to reschedule any appointments where you could accidentally infect other people. This includes pool parties, spa treatments, and even dental appointments (your dentist will likely send you home anyway). These wounds can also become infected with bacteria. If they don’t heal after 10 days, or if they develop a yellow crust, you should see your doctor (7).

How to Make Goodbye Last Forever

As we mentioned before, cold sores have a way of rearing back their heads whenever your immunity falls. They tend to be more frequent during the first year after the original infection, and will then get rarer with time. Make sure you are extra careful during those first few months!

This includes:

- Prevent sunburns by wearing sunscreen, hats, or a lip balm with high sun protection (SPF factor) during the summer. 

- Sleep well and keep healthy habits to boost your immunity.

- Avoid experimenting with any irritating facial products or new types of make-up.

- Avoid stress (easy right?).

If cold sores appear more than twice in two months or don’t heal fully in 14 days, talk to your doctor. You may need a more thorough course of antiviral medication.


1. Forkølelsessår, herpes simplex virusinfektion,

2. Looker K, Magaret A, May M, Turner K, Vickerman P, Gottlieb S, et al. (2015) Global and Regional Estimates of Prevalent and Incident Herpes Simplex Virus Type 1 Infections in 2012. PLoS ONE 10(10): e0140765.

3. John Hopkins University. (2020). Oral Herpes. Available online at

4. Cunningham A, Griffiths P, Whitley R, et al (2012) Current management and recommendations for access to antiviral therapy of herpes labialis. Journal of Clinical Virology 53(1):6-11.

5. Evans TG, Bernstein DI, Raborn GW, Harmenberg J, Kowalski J, Spruance SL. Double-blind, randomized, placebo-controlled study of topical 5% acyclovir–1% hydrocortisone cream (ME-609) for treatment of UV radiation-induced herpes labialis. Antimicrobial Agents Chemotherapy. 2002;46:1870–4.

6. Jensen LA, Hoehns JD, Squires CL. Oral antivirals for the acute treatment of recurrent herpes labialis. Annals of Pharmacotherapy. 2004;38:705–9.

7. Pray W. Nonprescription product therapeutics. 2d Edition, Baltimore, MD: Lippincott Williams & Wilkins, pp. 74-75.

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