There are a lot of "sensitivity" syndromes, and some are associated with genetic issues, some with toxicity, and others with mental health. And then there are questionable diseases [2]. Yes, the sufferers are sometimes vocal and unscientific. Those claiming to follow science shouldn't be.
[1] https://en.wikipedia.org/wiki/Culture-bound_syndrome [2] https://en.wikipedia.org/wiki/List_of_questionable_diseases