This easy-to-read title provides a comprehensive discussion of the major changes in daily life that have led to states of increased bodily inflammation.  Indeed, today there is an epidemic of allergic and autoimmune disease in the first and developing world. While outdoor climate change is now considered common knowledge, the impact of longer work hours, artificial lighting, increased food shelf life, and changes to the microbiome all have made a large impact in increasing allergies worldwide.  An allergy, best defined as a “damaging response from the Immune system due to a substance in the environment,” starts with warning signals, or generalized "symptoms," that are caused by something in the environment.  Itching, aches, pains, swelling, coughing, and fatigue are all immune responses.  Written in an engaging -- and often humorous -- style by an allergist/immunologist, the first three chapters outline how the humanbody is in an unquestionably harmful environment, and that, in general, the immune system is just doing its job.  In subsequent chapters, the specific topics contributing to allergies are covered in detail, starting with microorganisms and a focus on indoor living. Dust mites, for example, are addressed in one full chapter -- and for good reason.  The past few decades have seen an explosion of climate controlled, humidified indoor airspace that is ideally suited for more mass production of mites. In the end, emphasizes the author, all roads of inflammation from the environment lead to the “mast cell compartment.” The stress responses of the body summarily drive up this compartment and have led to a world-wide prevalence of between 14% to 17% of “mast cell activation syndrome.”  While genetics and comorbid conditions are important in any symptom or disease process, the mast cell compartment feeds and grows off all the major environmental changes of the past 50 or so years. This is why the human body in the 21st century is in a low level state of “rejection,” of the world, says the author. Most of these changes are irreversible, but the situation is not hopeless. Understanding how the body changes itself in response to its environment will allow controlled desensitization to the environment.  Allergic to Life: How the Human Body Rejects the Modern World serves as a concise and lively text for clinicians and general readers interested in a deep, expert dive into the world of allergy and immunology.