The only sulfur is that in the sweetener, acesulfame-K. Otherwise no. And it is, as mentioned spelled 'sulfur' (or sulphur, depending on where the speaker is from, US and UK have different spellings, I just spell it sulfur, its what I'm used to and I CBF trying to change the force of habit if I ever find out I'm on the 'wrong continent)
There ARE however 'sulfa' drugs, spelling as written, these are a class of antibiotics for the most part, based on, as a family, a sulfonamide backbone. Not all of them are antibiotics, there are other sulfonamide drugs however.
And some people are allergic to sulfa drugs as this class of compounds, IIRC has a similar rate of allergies to penicillins, about 3%. (I'm not trying to imply a correlation btw, between penicillin allergies and to sulfonamide antibiotics and other sulfonamides (the 'sulfa drugs' and the anticonvulsant sultiame, by which I mean, I am saying only that the rate of people being allergic, is approximately three percent, for penicillins, IIRC, and likewise, three percent for sulfa drugs, and not that one who is allergic to penicillin (beta-lactam group) antibiotics, is liable to cross-react. I suppose there are certain similarities, viewed with a certain slant, but thats just my chemical musing, and not relevant to allergies.
Also some unexpected sulfonamide sulfa drugs occur, , the anti-seizure drug sultiame, and more expectably, the thiazide diuretics (thio-, thia- and similar, indicate that there is a sulfur atom in a compound somewhere. In the case of the likes of the sulfa drug hydrochlorothiazide, one of the most wellknown thiazide diuretics, it has two sulfonamido moieties in its structure, and also, the -oxicam NSAIDs are all sulfonamides. Which appears to be, afaik, the moiety that acts as the 'trigger' pattern recognition entity, as with the beta-lactam group, its a sub-part of the penicillins and carbapenem antibiotics (a lactam being a cyclic amide, like a lactone is a cyclic ester, like GBL, but with an internal (cyclic) amide, that looks like, structurally, a cyclic carbon chain featuring -CCCCCR-NH-R(C=O)CCCCC- where - would be where the two ends loop together in a ring, and the carbonyl group of the amide, is of course, ortho to the nitrogen center.), and this sub-part is the bit, the beta-lactam group, that is unwelcomely
recognized by the immune system as a problem which must be assaulted and wiped out. Causing people to be damaged in the process, if one who is allergic to penicillins, or to sulfa drugs, takes the drug they are allergic to (drug class, rather)