“Well, you’d be anxious too if you couldn’t lick an envelope, couldn’t pick up your daughter in a car,” she’d reply. Finally, she found her way to holistic health, whose practitioners told her she had something called multiple chemical sensitivity. The American Medical Association, World Health Organization, and the American Academy of Asthma, Allergy & Immunology don’t recognize chemical sensitivity as a diagnosis. “Plasticizers, forever chemicals, you name it: These are all foreign chemicals.” They’re everywhere you look, in homes and offices, parks and schools. You can lose tolerance after one severe exposure, Miller says, or after a series of smaller exposures over time.