My friend had some rare type of bacterial vulvitis. It was when she was in high school. She told us a little TOO much detail. Anyway, she got it when she was in the ocean, apparently some jellyfish particles got up "in there" somehow. It caused a weird infection, she had to stay home for two months, then she was well for 6 months, then she had it for two months (stayed at home) again, then was fine. She knew that she could potentially relapse a 3rd time, but it didn't happen... For about 7 years - then it came back! She was getting her masters then, so she stayed at home a week or so but it took her several months before she was well. So I don't know if she will get it again but she said that this type had a somewhat definite cycle and after a lot of testing the gynecologist did figure out what exactly it was which always helps.
So I thought I'd contribute that. I don't know what treatments she used.