[Multiple chemical sensitivity: epidemiological, clinical and prognostic differences between occupational and non-occupational cases].

BACKGROUND AND OBJECTIVE The progressive increase in cases of multiple chemical sensitivity (MCS) syndrome and the lack of studies which associate the syndrome with possible occupational origins means that further research in this field is required. The objective of this study was to compare the epidemiological, clinical and prognostic aspects of cases of MCS of occupational and non-occupational origin. PATIENTS AND METHOD Observational study of patients diagnosed with MCS by the toxicology outpatients clinic of the Hospital Clinic of Barcelona between 2002 and 2007. The occupational and non-occupational origin of MCS was considered as an independent variable. The dependant variables were occupational activity, triggering agents of MCS, chemical agents associated with the development of clinical manifestations, severity of the symptoms, comorbidities and work disability. Percentages were compared between groups. RESULTS A total of 165 patients were included: The mean age was 47.7 years and 90.9% were women. There were significant differences between patients of occupational and non-occupational origin with respect to comorbidities such as chronic fatigue syndrome (68.1% versus 88.5%; p=0.002) and fibromyalgia (49.3% versus 73.9%; p=0.002), temporary disability (60.9% versus 39.6%; p=0.006) and permanent disability (8.7% versus 22.9%; p=0.006). CONCLUSIONS Cases of MCS attributed to an occupational origin had fewer comorbidities and less permanent disability than those of non-occupational origin.