I am allergic to Ceclor (caused all-over hives when I was younger). I just went to an Urgent Care that Rx Augmentin and I had notified the MD about my allergies (also allergic to Sulfa). I've been looking at information about Augmentin, and it says to tell my Dr if I have had an allergy to cephalosporins like Ceclor, but it doesn't say why. I'm a little leery - is it safe to go ahead and take if?