Having a “sulfa” allergy is quite common What is uncommon is understanding that being “sulfa” allergic does not necessarily mean that one is .
More information about Persulfate and sulfa allergy
Drug allergy, broadly called “hypersensitivity,” is an immune mediated response against a medication.  Hypersensitivity reactions may present either immediately within hour or be delayed between hours ..Allergy to sulfa drugs is a popular term for related medications. Once allergic sulfites, nickel and even tea laurel sulfate found in soaps, shampoos, etc. , can cause irritation or an allergic response..