i would say to go to your vet as soon as; it sounds like an allergic reaction.
my dog has the same sort of thing; he woke up in the middle of the night howling and when i went down to see what it was i saw that he was covered in lumps and could barely open his eyes. The vet said he may have been bitten or had an allergic reaction and recommended a hayfever product. We later found out it was a reaction to the franfurter sausages we were adding to his food to change it up a bit for him.
no one in the house has eaten them since :-)
