A hive. I get them, for some reason, when I eat a bagel with cream cheese. Now I'll bet that sounds really strange. I never eat cream cheese cold, not cooked in a recipe, unless it's on a bagel. Cooked down I never get a hive on my face. They are tremendously itchy but go away fairly quickly leaving a smaller bump for a few hours. I get only one of them too.
It could actually be just a pimple coming up.
My hunch is your right, a reaction to a bug bite, if it worsens you should see a Dr. if you think a allergic reaction is happening, tightness in throator chest, a feeling of closing of throat, call 911, dont try to drive self.