Armelagos, George J., and Kathleen Barnes. “The evolution of human disease and the rise of allergy: Epidemiological transitions.” Medical Anthropology 18, no. 2 (1999): 187-213.
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The concept of epidemiological transition is expanded to describe the evolution of disease in human populations. A.R. Omran observed that in modern nations pandemics of infections are gradually displaced by degenerative and “man‐made diseases.” In retrospect, Omran’s description is not the first example of an epidemiological transition. The Neolithic represents the initial epidemiological transition with an increase in nutritional and infectious disease. Sedentism, increase in population size and density, domestication of animals created foci of disease. We use the second epidemiological transition to understand the evolution of allergy in human populations. The high level of IgE in humans results in a super sensitivity to foreign proteins. Populations chronically exposed to helminthic parasites display high levels of IgE without any apparent adverse health effects. A blocking antibody provides a check‐and‐balance mechanism to the IgE‐levels. This mechanism was advantageous to both the host and pathogen. Without exposure to helminths there is apparently no IgG‐blocking antibody, the built‐in controls over the immune response to contact with foreign allergens is lost.