Yuck.
I had a sort of similarly odd situation once out on a walk during an retreat in high school. Something flew into my face--didn't really hurt at the time, I just thought it was a bug with bad aim or something. But by the time I got back from my walk, I had like an itchy pink marble on my forehead.
One of the retreat leaders offered me some Benadryl, which helped quite a lot (and I've used that since then, for random other itchy bites).
Have you tried any antihistamines? If you're worried about getting drowsy from Benadryl, you could also try topical anti-histamine cream instead, or a non-drowsy pill like Claritin?
I hope it clears up soon!
'09 Jamis Satellite Femme | stock Jamis Road Sport -- road
'08 Trek 7.2FX | Terry Cite -- commuter
'77 Raleigh Grand Prix mixte | stock Brooks (vinyl) -- just for fun!