Multiple chemical sensitivity: study of 52 cases

Multiple chemical sensitivity (MCS) is characterized by a loss of tolerance to various environmental chemicals. The objective of this study was to describe patients with MCS seen in our hospital. Patients consecutively seen by the Toxicology and Chronic Fatigue Units who presented symptoms of MCS were included. The diagnosis was clinical. All patients completed the Quick Environmental Exposure and Sensitivity Inventory (QEESI) questionnaire. Fifty-two patients were included. The average age (standard deviation) was 47.2 (7.6) years, and 46 (88%) were females. The origin of the syndrome was related to occupational exposure to various chemical agents in 31 cases (59.6%), including occupational accidents in 14 patients (fumigation of the workplace with insecticides). In 20 patients (38.5%), the syndrome could not be associated with any toxic exposure and was considered a manifestation of chronic fatigue syndrome. The QEESI showed mean scores of 72.9 (18.6) on the chemical inhalant intolerance scale, 45.5 (20.6) on the other intolerances scale, 69.8 (20.6) on the symptom severity scale, 4.4 (1.8) on the masking index and 66.6 (21.7) on the life impact scale. All patients were followed up for a minimum of 12 months, and during this period they remained stable with no deaths. MCS normally affects middle-aged women. It is frequently triggered by exposure to chemical agents, especially insecticides. An association with chronic fatigue syndrome is common. The prognosis is good but the patients' quality of life is seriously affected.