So I know a cause for hives is very hard to find, but anything at all would be helpful!
It happens very infrequently, maybe once a month at the most, but almost out of the blue at no special time of the day, a singular hive will appear around my lips. It's never quite in the same place, and lasts only for about 45 minutes, but it is always over/under one of my lips and is quite painful during the duration. The fact that it occurs sometimes when I wake up before I have ingested anything seems to rule out an allergic food reaction (to me at least), and the fact that it sometimes occurs when I'm simply driving or sitting in class seems to rule out a bug bite or something of the sort. I usually just sit and wait it out, or ice seems to dull the pain.
Any suggestions to what could be causing it or how to make it a little less painful during the duration would be appreciated, thanks!