2022 Volume 59 Issue 1 Pages 37-50
Environmental hypersensitivity (environmental intolerance) is a health disorder characterized by a variety of systemic symptoms, including autonomic and endocrine symptoms, immune and allergic symptoms, chronic pain and fatigue, memory and emotional disorders, and hypersensitivity to external environmental stimuli in daily life (light sensitivity, sound sensitivity, smell sensitivity, air pressure sensitivity, chemical sensitivity, and electromagnetic sensitivity). Typical examples of environmental hypersensitivity are sick house syndrome, chemical sensitivity, and electromagnetic hypersensitivity. The pathological mechanism of environmental hypersensitivity can be explained by the three-stage hypothesis: the genetic, initiation, and triggering stages. The first stage is the presence of genetically determined factors related to the stress response. In the second stage, an individual exposed to environmental factors becomes susceptible to intolerance of environmental stress. In the third stage, environmental stress at a daily level which would not bother normally healthy individuals develops in a sensitive person resulting in general physical problems. In recent years, the rapid increase in the number of patients with environmental hypersensitivity has become a worldwide problem, and although its pathogenesis remains to be elucidated, a close relationship with allergic diseases has been identified. Over the past 30 years, Hojo has conducted multifaceted epidemiological investigations, including the preparation of a Japanese translation of the international common questionnaire for evaluating environmental hypersensitivity, confirmation of its reliability and validity, and the setting of screening thresholds unique to Japan. In this paper, we describe the latest findings on environmental hypersensitivity and introduce some of the epidemiological studies conducted by the authors in Japan using the international common questionnaire.
