Again requesting FAS fact-checking on my posts especially since we're talking sulfites but reading that OP's post it's too much shotgun approach. I think if she's suspecting a fish allergy and has a diagnosed IgE-mediated shellfish allergy it's time for some in office challenges. This is all assuming OP is the one who is tiring of a super restricted diet. I'm not familiar with how natural sulfites in foods factor in to avoidance and types of reactions or how similar/different it is to food allergy but in light of the severity of known reaction history I'd think seeing through the grouper first would be a logical next step. Chasing naturally occurring sulfites in foods seems like, well, a chase if the big ticket hive-inducing foods aren't resolved.