Hi I Have Four What I Presume To Be Bites

Hi I have four what I presume to be bites I received yesterday (not sure how or when) that are now each swollen the size of a quarter to half dollar. My entire arm is throbbing. I put hydrocotisone on them and have minimal itching. Should I be concerned with the throbbing pain or is it possibly a fibro flair (although it is just the arm).