Cold sores, also known as fever blisters, are caused by the herpes simplex virus (HSV). There are two types of HSV: HSV-1 and HSV-2. Cold sores are usually caused by HSV-1, while genital herpes is usually caused by HSV-2.
Cold sores are not considered a sexually transmitted disease (STD), but it is possible to transmit the virus to another person through skin-to-skin contact or through oral sex. It can also be contracted by other means such as sharing personal items or through close personal contact with an infected person.
It’s not possible to prevent infection with the herpes simplex virus or prevent outbreaks of cold sores, but you can take steps to minimise the spread of infection.
Cold sores are at their most contagious when they burst (rupture), but remain contagious until they’re completely healed. Avoid close contact with others until your cold sore has completely healed and disappeared. However, there’s no need to stay away from work or miss school if you or your child have a cold sore.
You can help minimise the risk of the cold sore virus spreading and cold sores recurring by following the advice below:
- avoid touching cold sores unless you’re applying cold sore cream – creams should be dabbed on gently rather than rubbed in, as this can damage your skin further
- always wash your hands before and after applying cold sore cream and after touching the affected area
- don’t share cold sore creams or medication with other people as this can cause the infection to spread
- don’t share items that come into contact with the affected area, such as lipsticks or cutlery
- avoid kissing and oral sex until your cold sores have completely healed
- be particularly careful around newborn babies, pregnant women and people with a low immune system, such as those with HIV or those having chemotherapy
- if you know what usually triggers your cold sores, try to avoid the triggers – for example, a sun block lip balm (SPF 15 or higher) may help prevent cold sores triggered by bright sunlight