Dunster is right.. sulfates and sulfa antibiotics are two different things.. however.. the research folks are finding more that there are folks who have allergies to ingredients in neosporin..frequently it's a developed allergy to the neomycin when it is absorbed into the skin and gets into the system.
http://www.pdrhealth.com/drugs/otc/o...contentId=3485
That is a link to the on-line PDR.. you'll notice it does not mention cross over allergies with sulfa drugs. However.. you can be allergic to anything...