Cold sores signify you've been infected by the herpes simplex virus, probably HSV-1 (this is the type 1 strain, in the place of the type 2 strain, HSV-2, which will be generally responsible for genital herpes). The herpes virus currently has no known cure so after you are infected you've got the virus for life and could never remove it, I'm sorry to say. Even though, you should be aware that there are several herpes vaccines in-the works right now that are looking very promising and may be used in the future to vaccinate people against Cold sores in addition to vaginal herpes.
Herpes on average 'hibernates', as we say, dormant in the sensory nerve cells close to the site of initial infection, which will be usually round the mouth but may also be numerous other areas like the nose, eyes, and finger and toe nails. All through an active stage where there are noticeable sores (treatment for cold sores), the virus goes active and replicates very aggressively on the surface of your skin, thus triggering said cold sore. This active period will usually last between 2 and 21-days, with weekly being about average for most people. Mind you, the fre-quency, length, and severity of outbreaks will decrease over time as you body builds an immunity to herpes, with a few people who have been attacked for years or decades going years between outbreaks, though they'll never fully end.
Oral herpes is usually transmitted when there are visible blisters on the person's face, however the period immediately before and after having a cold sore exists is a period when the individual is asymptomatically shedding the virus and is thus capable of infecting other people although there are no outward signs of the condition. This period of asymptomatic shedding often lasts about a week, so you must remember the fact you are likely still infectious a week before and after you get a chilly sore.
More details is found on this article.
A cold sore on your nose is no unique whatsoever from the more common cold sore on the mouth or top, and must be treated in precisely the same manner. The best options are prescription anti-virals, such as acyclovir and valacyclovir, in proper combination having an successful home treatment program, such as using benzyl alcohol, lysine supplementation at the proper dose, keeping the cold sore treatment clean, dry, and cleared, etc. I've found through analysis over time that with the device I've using these things, I can frequently prevent a cold sore before it ever happens by starting treatment the moment I feel the tell-tale pain of an oncoming episode, and if one occurs I can usually be rid of it inside of 24-48 hours.