From Main Meta Stack Exchange: How can we get rid of misspelled and unused (or "zombie") tags?.
If a misspelled tag is perceived only when it was used in a couple of questions, then, it could be edited out like you did (but as suggested in MSE, if it is a tag used in many questions first seek some feedback from community before engaging editing). Then, it will go away as Mapperz said.
Whenever you see such situation you have some options: bring the subject to meta, bring it up on chat or flag the question for 'moderator attention' and explains the situation.
There are other options on the table (not exactly related to misspellings, but avoid creation of undesired tags): like to blacklist it (avoid the tag to be created). However, this is more for undesired tags that could come up with certain frequency (for example, "gis").