threading or epilation could cause bacterial infections

I don't think that threading would do that. No more than plucking the hairs (actually, it's less!) Threading has been around for a really really long time, and it one of the best methods of hair removal for woman on the face and arms.

I've known girls who regularly get threading done and none of them are suffering from bacterial infections! Maybe it depends upon the environment in which threading is done or the person's skin condition. Some people have extra sensitive skin which reacts to shaving, threading or waxing. As for me if i shave everyday my face gets all red and scratchy! so i shave after every 3 days.