The most common mistake people make is to subject persons with sensitivities to a reverse onus when they report their experience of repeatable, controllable circumstances, contrary to ethics, social convention and laws since the Magna Carta. This practice is unethical in any context, but becomes especially damaging in clinical medicine.
Ignaz Semmelweis saved the lives of thousands of women decades before Lister discovered the role of germs in disease. In fact, contrary to how it's taught in most science courses, infection was a known cause of disease and death centuries before Lister identified the role of germs.
Public service unions like CUPE might fight to protect their members from getting headaches from perfume, but they do so in a way that manufactures consent for ploughing under and killing patients with undiagnosed sensitivities in health facilities where their members work.
Institutions charged with addressing attitudes betray their constituencies by remaining silent while their funder promulgates lethal misconceptions. At Women's College Hospital, for instance, long-known mainstream knowledge is obscured behind revisionist models. Persons with sensitivities are robbed of their history. Separate health issues are arbitrarily confused.
Children with undiagnosed sensitivities, along with other vulnerable people, are being injured and killed in health care. Canadian authorities and Canadian political parties invisibilize protective measures Health Canada was encouraging prior to 1993.
In 1985, Eugene Garfield, PhD, President & Founding Editor of The Scientist provided an excellent overview of medical literature about sensitivities. Garfield documents several approaches, as described in scientific and medical literature before the discussion was subsumed under debate about the approaches of doctors of environmental medicine.