Cold sores are notoriously difficult to treat - even Hollywood stars Katie Holmes and Lindsay Lohan, with their considerable resources, haven't managed to find a successful treatment for theirs.
Often the butt of juvenile sniggering because of their unjustified association with sex and STDs, cold sores are in fact a fairly common but undiscussed illness.
And far from being a subject of humour, the unsightly blistering can bring untold misery, affecting sufferers' physical and psychological health. Ballymena mum-of-two, Eve Marrs had them for 40 years.
"As soon as one cleared up, another would appear," says Eve (63). "They'd leave red scars. They were quite serious and nasty-looking - no-one wants to be seen with cold sores and you have to be careful not to pass them on to others, so extra care has to be taken using cups, cutlery and so on.
"When they begin to erupt, lipstick has to be avoided and being careful with face flannels and towels is a necessity. It really is embarrassing when they appear."
"I couldn't cover them with lipstick because I didn't want to reinfect the area. I just put on creams; I even tried putting after shave and perfume on them to try and kill them. Absolutely nothing worked. I felt so self-conscious."
Eve stayed at home to bring up her sons Gary (38) and Ryan (33) before going out to work at children's play groups. When her cold sores worsened, she went to see her GP.
She says: "He recommended a well-known cream, but it was no use. I felt the tingle again in no time - it was very disappointing. I thought I was never going to get rid of them but I looked online last year and found a brand called Lipivir. "I didn't expect a miracle but I thought, 'Why not try it?'. I'm very glad I did."
Lipivir is made by the innovative Swiss firm, Devirex. A lemon-scented liquid gel, it contains polyethylene glycols to prevent the eruption of blistering, rather than treat the notoriously stubborn virus. The gel is light and free from the common side effects of other topical products.
"When I put it on, it took the itch away immediately and the sore never reached the horrible crusty blister stage," Eve explains. "There was no sting or any side effects at all. To me, it was like magic - a Godsend. I just dabbed it on when the dreaded warning tingle began and it didn't get the chance to become a full-blown cold sore.
"I can't really believe it myself, but after using it a few times I have now been totally free of cold sores for approximately eight months - that is a record for me."
Eve was delighted to discover that make-up, facial creams and cosmetic products can be worn on top of lipivir, without causing undesirable results. For the first time in 40 years, she can wear her favourite lipstick as often as she wants.
"I like Max Factor's dusky pink. My cold sores were so visible, everyone noticed them. I know there's a stigma attached to them, but I was very lucky not to have been called names or anything. People understood. But now they're noticing my lipstick instead."
- Belfast Telegraph