Allergy emerged as a significant modern malady, transforming from an unknown condition to a widespread concern within a century. Mark Jackson's work traces the historical trajectory of allergies, revealing how conditions like asthma and eczema, once considered rare afflictions of the elite, became diseases of great medical, cultural, and political importance by the late 20th century. The book explores how allergy became emblematic of 'diseases of civilization,' prompting global discussions on the interplay between human health and the environment, and fueling anxieties about the consequences of modern lifestyles.

The book is presented as a groundbreaking historical account of allergy. It is framed as a significant exploration of how a set of conditions became a major medical, cultural, and political issue. The work is noted for its examination of allergy as a 'disease of civilization' and its connection to environmental and modern living concerns. The narrative aims to demonstrate the profound shift in understanding and impact of allergies over the course of a century.