This is Fresh Air, I'm Dave Davies.

When my guest, author and medical anthropologist Theresa McPhail finished researching and writing

her new book, she made some lifestyle changes.

She stopped taking daily showers and changing her sheets as often, along with eating more

natural food and making sure to get enough sleep and exercise.

Her book is about allergies, which are a growing challenge for humanity as our environment

changes.

In the US, nut allergies in children, hospital admissions for asthma, and prescriptions for

epipans which treat extreme allergic reactions have all tripled in recent years.

Estimates are that 30-40% of the world's population now have some form of allergy.

Some allergic reactions are anusense, the congestion and burning eyes that come with a high

pollen count, and some are deadly, like anaphylaxis that can follow a bee sting.

McPhail has had personal experience with in her own family.

There are allergies to airborne irritants, food allergies, and skin allergies.

McPhail found the causes of allergies to be complex and often misunderstood.

For decades, they were thought to mainly afflict people who were nervous, anxious, or temperamental.

While there's new science on the causes of allergic reactions, effective treatments

are hard to come by and expensive when one shows promise.

Theresa McPhail is an associate professor of science and technology studies at Stevens

Institute of Technology in New Jersey.

She researches and writes about global health, biomedicine, and disease.

She holds a PhD in medical anthropology from the University of California, Berkeley, and

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