Small mosquito-like bump on face that comes and goes

[brittb93]

I have a small mosquito-like bump that occasionally shows up on my face every once in awhile (probably every other month) and it itches like CRAZY every time I get it. It usually only lasts for a couple hours and then it completely disappears and the itch goes away and it's always just one tiny bump. Sometimes it shows up by my eyebrow but usually right above my upper lip. Does anyone have any idea what this could be? I haven't noticed any patterns or triggers that could cause this and the itch is so bad it's almost impossible to ignore.