So, short version, I was out in the woods with my girlfriend we were by the beach so I didn't have my shirt on and I was in shorts, we walked through a chunk that was hugely infested by mosquitoes. So, now I have about 50 bites (my estimate) all over my back and legs, I just want to know if there's any potential bad thing about that and how long should they take to heal up? (This happened Thursday 17th)

There is potential that you may contract West Nile Virus (click for info), but it is typically only fatal in infants and the elderly.

Mosquitoes flock to me when I go camping. The best advice to help the bites heal quickly is not to scratch them (they will become open sores if you do). Typically they itch for 2-3 days and disappear within a week.

Click here for an article concerning treating the bites (addresses itchiness primarily).

All right thanks, I figured about the not scratching part. And I'm not too worried about West Nile.

Yeah, just get some kind of itch cream. You can ice them if they are really itchy, as well, I've found that helps. Or maybe a cold bath

If you have no itch cream readily available, minty toothpaste does wonders.