OL SOR S: WHAT YOU N TO KNOW · What causes cold sores? Cold sores are caused by a virus called herpes simplex virus (HSV). HSV comes in two forms: HSV-1 and HSV-2. Either type can

COLD SORES: WHAT YOU NEED TO KNOW

Copyright © medSchool For You 2015 1

1. What is a cold sore? A cold sore is a common skin infection. It causes a small group of blisters to

appear around the lip and mouth area. These blisters may break open, leak

fluid and crust over. They usually last for up to 2 weeks before healing

completely.

What causes cold sores?

Cold sores are caused by a virus called herpes simplex virus (HSV). HSV comes in two forms: HSV-1 and

HSV-2. Either type can cause cold sores but HSV-1 does so most often. There are also two types of

infection, the first infection and recurrent (repeat) infections.

First (primary) infection

The first outbreak of a cold sore happens when the virus enters your body for the first time. It is usually

more severe and lasts 1-3 weeks. The first infection starts with fever, fatigue, difficulty swallowing and

swollen lymph nodes in the neck. Painful cold sores may involve the entire lining of the mouth and both

lips. It is common for some people to never have symptoms of a first infection.

Why do I keep getting them?

Recurrent infections

Once the first infection clears up, the virus stays in the body and may cause cold sores to return

throughout your lifetime. This is because when the virus is not active on the surface of the skin it

DID YOU KNOW?

Cold sores and fever blisters are exactly the same thing.

DID YOU KNOW?

About 60-95% of adults are infected with the cold sore virus5. It is a very common

condition.



remains in a sleeping state inside your cells until a trigger reactivates it causing the cold sore to come

back. Some people don’t suffer any recurrences whereas others can have 10 or more per year.

Recurrent infections are usually less severe than primary infections. They don’t last as long, sores are

smaller and don’t normally cause other symptoms like fever or fatigue.

Do I need treatment? What’s the prognosis?

Cold sores will go away without treatment after 7-14 days. Unfortunately there is no way to cure the

infection. Both prescription and non-prescription treatments help with the symptoms, decrease cold

sore severity and help shorten the time you have them.

2. How did I get the virus? The cold sore virus is highly contagious and can spread through contact with active sores. It can also

spread by:

Sharing drinking glasses, eating utensils, lip balm, towels or creams of an actively infected

person

Kissing or touching their saliva

Touching the blisters or fluid directly

While a cold sore is most contagious during an active outbreak, there is also the possibility of spreading

when there are no symptoms at all. The highest likelihood for spreading the virus are the few days

before the cold sore is about to erupt (even before the tingling, burning or itching) and few days after

the sore has healed. Take extra care to avoid touching the area during these times to prevent spreading

the virus to others.

Who’s at risk?

Anyone who comes into skin to skin contact with a person infected by the virus can catch the infection.

3. How do I know if I have one?

Signs and symptoms

- Cold sores are most common on the lips and mouth

- Tingling, burning or itching starts about 24 hours before the cold sore appears – this is called the

“prodrome phase”

DID YOU KNOW?

Up to 40% of people 20 or under are infected with HSV-1, increasing to 65% in

those older than 70.6



- Cold sores look like one or a small group of painful blisters on one side of the lip or mouth area

with a red base

- Blisters eventually break and leak a clear fluid that eventually starts to crust or scab

- Without treatment, healing occurs without scarring in 1-2 weeks

- Some people may be infected with the virus but never show any symptoms

Example of what a cold sore looks like:

Cold sore checklist3:

Likely a cold sore Possibly NOT a cold sore

Tingling, itching or burning in the area before the sore develops

Appearance of fluid filled blisters on the lip

Blisters have broken, leaked a clear fluid

Crust or scab formation

Complete healing in 7-14 days

Come about after long sun exposure

Having honey-coloured crusts

Sores on the inside of the mouth or lips

Sores spreading to other areas of the body

Lasts longer than 14 days

Sore is very swollen, red, has pus or blood

Other symptoms like fever, fatigue, nausea/vomiting

No history of ever having cold sores before

4. What can I do to prevent them? Applying sunscreen with an SPF of at least 30 to the face

and lips can prevent cold sores triggered by sunlight

Avoid touching your cold sores

Most adults are infected with the virus but only 20% of people who are infected

with actually get cold sores. That means about 80% of adults with the virus are

unaware they are even infected and can still pass the infection to others.5



Wash your hands often, especially after applying a cold sore cream or touching the area

Do not share creams with others or items that come into contact with the lips and mouth such

as lipsticks, or cutlery

Avoid kissing or oral sex, until your cold sores have completely healed

If you have a cold sore, be particularly careful around newborn babies, pregnant women, and

people with a low immune systems such as cancer patients

Lower your stress. You can do this through relaxation exercises (e.g. yoga, meditation) and

getting enough sleep can help prevent future cold sore outbreaks.

What triggers a cold sore?

There are many things that will trigger a cold sore. Some of these triggers can be avoided and prevent

future cold sores. They can vary from person to person, the most common are:

Triggers can be divided into 3 categories: Weather Physical Procedures

Sun exposure or UV light (e.g. tanning beds)

Cold weather or wind

Stress or anxiety

Fever or illness (e.g. cold or flu)

Trauma

Fatigue

Menstruation, pregnancy or other hormonal changes

Dental work (e.g. tooth extractions)

Chemical facial peels

Chemotherapy

Oral or facial surgery

REMEMBER Cold sores are very contagious so try to avoid touching them, washing your hands often

can help to avoid spreading the virus to another part of your body or to another person.

HELPFUL TIP!

Writing down what causes your cold sores in a journal can be helpful. This way you can try to

avoid these triggers and prevent new cold sores. Suggested items to write down include:

- Date your cold sore started

- Any unique activities or events around the time of the breakout (e.g. stressful

life events, dental procedures)

- Amount of sun exposure

- Physical or hormonal changes (e.g. females to document last menses)



5. What treatments are available? Non-medication strategies to help with your cold sore:

- Application of protectant creams like petroleum jelly,

zinc oxide or cocoa butter to prevent cracking or drying

of the sore

- Keep cold sore clean by gently washing with mild soap

and water

o Cleaning can also be done by soaking the area

with cool compresses of water

- Gently dab creams on the sore rather than rubbing them in to prevent bothering the area more

Over-the-counter products:

- 10% docosanol cream (Abreva®)

o Applying this cream has been shown to shorten healing time by up to 1.5 days and the

time you have pain by half a day

o Works best as soon as you feel any burning, tingling or stinging (prodrome phase)

o Side effects: sometimes causes mild burning or stinging

- Local anesthetics - benzocaine, lidocaine, prilocaine, pramoxine (e.g. Orajel®)

o Works by numbing the area to relieve pain and itching, however does not help the

healing time or severity of the cold sore

o Can be used anytime during the time you have a cold sore

o Side effects: sometimes causes mild burning or stinging

Prescription medications:

Acyclovir 5% cream (Zovirax®)

Acyclovir 5% + hydrocortisone 1% cream (Xerese™)

Acyclovir, valacyclovir, famciclovir tablets

What is it? Topical antiviral Topical antiviral plus steroid (anti-inflammatory)

Oral antivirals

Does it work?

Lowers the length of time you have the cold sore, time to crust formation

No effect on lowering pain

Shortens healing time and reduces size of cold sore

42% of people who used this cream as soon as they felt the burning or tingling, never got a cold sore

Faster healing time and less time you have pain

When do you start

All treatments are best started as soon as you feel the first symptoms of a cold sore (within 1 hour of first sign of tingling, itching or stinging = prodrome phase)



treatment?

How do I take it?

Applied 5 times per day for 5-10 days

Taken by mouth

*Speak to your doctor or pharmacist to decide which is best for you

Side effects Well tolerated;

Possible mild burning or stinging at site of application

Nausea, diarrhea, headache

Caution if you have kidney problems

Speak to your doctor or pharmacist to see which cold sore medication will best suit you.

My friend told me about some home remedies. Do they work?

Home remedies like using rubbing alcohol, witch hazel or excessive

cleaning/scrubbing of the sore are NOT RECOMMENDED because they

dry out the cold sore and cause more cracking and pain.

Applying ice may help with pain and swelling but will not make the

cold sore heal faster.

I have had the cold sore for 3 days… what do I do now?

Without treatment, cold sores typically last anywhere from 7-14 days.

All current products only work when started as soon as you feel your

symptoms. After a few days, most medications will not help. Consider

protecting the area with some petroleum jelly or using ice to help the pain. Let your doctor or

pharmacist know if it does not seem to be getting better or is getting worse.

6. When should I see a doctor? - If the cold sore lasts longer than 14 days

- You have other general symptoms of illness, such as:

o Fever

o Swollen glands

o Tiredness and fatigue

NOTE: There is no benefit to using a cold sore cream every day to try and prevent

future cold sores. They cannot cure the virus and will only work when the cold sore

is starting.



- You have a weakened immune system:

o You’re taking medications that decrease the immune system (e.g. steroids, tacrolimus)

o You have a disease that suppresses your immune system (e.g. HIV, recent transplant)

- If the cold sore is extremely red, swollen or contains pus

- If you are not sure it is a cold sore or think it is something else

7. Where can I get more information?

Resources:

HealthLinkBC

References 1. J.S. Conklin. Cold Sores (herpes labialis). In: Patient self-care, 2

nd edition. Ottawa: Canadian Pharmacists Association;

2010:889-895.

2. Canadian Family Physician. Treatment and prevention herpes labialis. 2008; 54:1683-7.

3. medSask. Cold Sore – Guidelines for prescribing oral antivirals. 2014. Available from

http://medsask.usask.ca/professional/guidelines/cold-sore.php

4. C.S. Miller, R.J. Danaher. Asymptomatic shedding of herpes simplex virus (HSV) in the oral cavity. Oral Surg Oral Med Oral

Pathol Oral Radiol Endod, 105 (2008), pp. 43–50.

5. M. Fatahzadeh, R.A. Schwartz Human herpes simplex virus infections: epidemiology, pathogenesis, symtpomatology,

diagnosis and management J Am Acad Dermatol, 57 (2007), pp. 737–763.

6. S.B. Woo, S.J. Challacombe Management of recurrent oral herpes simplex infections Oral Surg Oral Med Oral Pathol Oral

Radiol Endod, 103 (Suppl) (2007), pp. S12.e1–S12.e18.

7. Cernik C, Gallina K, Brodell RT. The treatment of herpes simplex infections: an evidence-based review. Arch Intern Med.

2008;168(11):1137.

8. Lexicomp e-resource. Acyclovir (topical) drug monograph. Accessed March 11, 2015

http://online.lexi.com.myaccess.library.utoronto.ca/lco/action/doc/retrieve/docid/patch_f/1768319

9. Lexicomp e-resource. Acyclovir (systemic) drug monograph. Accessed March 11, 2015


10. Lexicomp e-resource. Acyclovir and hydrocortisone drug monograph. Accessed March 11, 2015


11. Lexicomp e-resource. Valacyclovir drug monograph. Accessed March 11, 2015


Your pharmacist is a knowledgeable and trusted resource. Ask them any questions you have about

cold sores!

http://www.healthlinkbc.ca/healthtopics/content.asp?hwid=hw31977

http://medsask.usask.ca/professional/guidelines/cold-sore.php







12. Lexicomp e-resource. Famciclovir drug monograph. Accessed March 11, 2015



Documents

OL SOR S: WHAT YOU N TO KNOW · What causes cold sores? Cold sores are caused by a virus called herpes simplex virus (HSV). HSV comes in two forms: HSV-1 and HSV-2. Either type can