Antiviral creams €“ these contain aciclovir or penciclovir to stop the virus from multiplying. They can prevent blisters from increasing in size and speed up healing time. To be most effective, they should be applied at the tingling stage, although they can be used on blisters that have formed. Aciclovir can be used by adults and children €“ it should be applied five times a day for five days during waking hours. Penciclovir should only be used by those over 12 years and needs to be applied every two hours during the day for four days. Antiviral creams should only be used for current outbreaks of cold sores €“ they cannot get rid of the virus or prevent cold sores from occurring. Examples: Zovirax, Fenistil.

Patches €“ these contain hydrocolloid particles (also used in dressings for wound healing) to help soothe and heal cold sores. They hygienically seal the sores to prevent the virus from spreading and make them less visible. They can be placed over the cold sore at any stage, although they are most effective when used at the tingling stage. They should be worn 24 hours a day until the cold sore has healed. When a patch naturally detaches after about eight hours it should be replaced with a new one. They are suitable for use by adults and children. Example: Compeed Total Care Invisible Cold Sore Patch.

Light technology €“ this is a device that delivers a narrow waveband of light to boost the skin's natural ability to fight the cold sore virus at any stage of an outbreak. It can reduce healing time and prevent a cold sore appearing when used at the tingling stage. It is typically held over the affected area for three minutes up to three times a day for two or three days. Some have been shown to reduce the severity of cold sores and the incidence of future outbreaks. They can be used by those aged 16 years and over. Example: LipZor Light Device.

Other topical treatments
There are a variety of other creams and gels that contain local anaesthetics, astringents, antiseptics and moisturisers to help relieve the symptoms of cold sores. Anaesthetics (e.g. lidocaine) help to numb the area and relieve pain. Antiseptics (e.g. cetrimide) can help to prevent further infection, and astringents or drying agents (e.g. zinc sulphate) can help to dry up the cold sore. Moisturisers (e.g. dimeticone) protect the skin and prevent scabs coming off too early. These products are safe for use by adults and children. Examples: Blistex, Cymex, Lypsyl Cold Sore Gel.