In the recently released Netflix movie, Bright, Tikka uses the Wand and shortly thereafter starts having health issues (black creepy stuff) that she needs to be healed from. It was not clear to me what made her need the healing, since her other uses of the Wand had no similar side effects.
While the movie wasn't indeed to forthcoming with information, there're bits and pieces that make suggestions. I also recommend to check "History of Magic" video released by Netflix:
According to the video, the first Magic Wand was created from the corpse of the greatest wizard in history, Sargon, after he fell victim to a magic annihilating virus created by the Dark Lord. The visual of the virus was very similar to what happened of Tikka: mysterious quick spreading dark tendrils.
Basically it looks like there's a virus which turns brights into Magic wands. Or maybe the virus is some kind of dark influence, not unlike what happened to ring-bearers in "The Lord of the Rings". I'm sure this topic will be touched in sequel one way or another.
Another (and much more interesting) question is how she caught this bug: maybe she already had it and massive amount of magic required to resurrect somebody just quickened it. Or maybe it's wand which was contaminated by it (the wand is probably just somebody who died because of this virus). Or maybe it happened because she tried to heal an orc, a member of the race aligned with Dark Lord couple of millenniums earlier. I don't know, hopefully "Bright 2" explains those things to us.