Subjective symptoms, onset/trigger factors, allergic diseases, & exposures in Japanese patients with multiple chemical sensitivity

Abstract

Overview

Recently, due to rapid changes in the Japanese lifestyle, the clinical condition of patients with multiple chemical sensitivity (MCS) may also have changed. The latest survey reviews subjective symptoms, ongoing chemical exposures, the prevalence of allergic diseases, and presumed onset/trigger factors in patients with MCS, comparing results with those from a decade ago.

Methods

• The recent survey spanned 2012 to 2015, with prior data collected from 1999 to 2003.
• Patients were diagnosed at five medical institutions specializing in MCS.
• Participants included 111 patients in the new survey and 103 in the prior survey. The controls consisted of the general population, with 1313 participants in the new and 2382 in the old survey.

Findings

• Decrease in certain chemical exposures: A decrease was noted in patients' exposure to insecticides and second-hand smoke over the decade.
• Increase in chemical intolerances: Scores for chemical intolerances, other intolerances, and life impacts increased significantly in patients.
• Growth in allergic diseases: A significant rise in bronchial asthma, atopic dermatitis, allergic rhinitis, and food allergies was observed among MCS patients.
• Diversification of onset/trigger factors: Electromagnetic fields, perfumes, and medical treatments have become more significant onset/trigger factors, reflecting an increased diversification over time.

Conclusion

There has been an increase in avoidance behavior toward chemicals, presumed to aggravate MCS symptoms. This shift correlates with significant changes in chemical intolerances, life impacts, and the prevalence of main allergic diseases in MCS patients. Overall, the diversification of onset/trigger factors point towards a broader environmental sensitivity in the population.