” Secondly, what you describe, in the absence of a skin rash of some type along with the “itchiness” is probably not an allergic
reaction. Were it an allergic
reaction, however, it could be an allergic response to certain classes of antibiotics; for example Biaxin and Zithromax are in a class of drugs called Macrolides so that, if allergic, you might be allergic to all antibiotics in that Class.