Since I set all of my guitars up for down tuning of some variety, I ALWAYS put fresh strings on new guitars. Even if I didn't need to set up my guitars for alternate tunings, I'd still change strings. God only knows what kind of ambient environmental conditions the guitar was exposed to while in transit from the factory, to a warehouse/dealer, then to me. In the situation where a guitar is coming from a dealer, if it's been hanging on the wall, I guarantee that it's seen some play. Pull the old strings, give the fretboard a wipe down with a clean dry towel and put a new set of strings on. If your body chemistry is such that this is a problem with this guitar, try using coated strings like Elixir, Cleartone, or the like. Just keep in mind, STRINGS ARE CONSUMABLE/PERISHABLE. They are not mean to last months on end. On any of my gigging guitars, I average three or four gigs before I need to change strings.