A cold sore is a small cluster of blisters that usually form on or around the lips. They can also appear around or inside the nose but most commonly appear around the mouth. A couple of days after the blisters appear, they will crust over, taking on a yellowish appearance. They can be painful and tend to last around a week.

What causes cold sores?

Cold sores are caused by a virus called Herpes Simplex. This is an extremely common virus that most of us carry. Commonly, we catch this virus as children and it remains dormant within us. Most people will carry the virus but never experience any symptoms from it.

Some people who carry the Herpes Simplex virus will develop cold sores once or twice a year. This tends to be when we are tired or run down. The virus can also be activated by sun light, causing a cold sore to appear.

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Are cold sores infective?

Yes, cold sores are infective, particularly when the blisters have first appeared. Once the blisters have crusted over, the sore is much less infective but it is still a good idea to avoid contact as much as possible while you have a cold sore. Try not to touch the area and if you do, be sure to wash your hands. Avoid kissing to avoid spreading the virus.

Be extremely cautious not to touch the cold sore and then touch your eyes as it is possible to transfer the infection. This can be a really nasty infection and can ultimately lead to loss of sight. Signs that the infection has been spread to your eye include pain, redness and blurred vision. If you suspect that the virus has affected your eye, contact your doctor immediately.

Can cold sores be treated?

Yes. Antiviral gels that contains medications such as acyclovir can be helpful, especially straight after the cold sore has appeared. These are available over the counter at pharmacies. Follow instructions on the packet to keep the area comfortable and allow it to heal.

Again, make sure that you wash you hands once you have applied any gel or cream.

Can I have treatment with my dentist while I have a cold sore?

Most dentists are happy to treat patients while they have a cold sore, especially if the cold sore has been through the infective phase of blisters and has crusted over. However, some dentists are not happy to treat you with an active cold sore. It is always a good idea to check before visiting the dentist.

Should I visit my doctor?

If you have a cold sore, you do not usually need to visit a doctor. They will normally heal on their own and you can help the process by using antiviral gels as mentioned above.

However, if the cold sore has not healed after 2 weeks or you are aware that you have a weakened immune system, you may need to visit your GP.

As mentioned above, if you suspect that the Herpes Simplex virus infection has been spread to your eye, you should contact your doctor immediately.

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