Allergological and Toxicological Aspects in a Multiple Chemical Sensitivity Cohort

Abstract

Background. Multiple chemical sensitivity (MCS) is a chronic condition characterized by an exaggerated response to toxicants. We ascertained the prevalence of allergy to metals and toxicological aspects in MCS patients.Methods. We conducted a retrospective review of medical records of 41 patients with MCS. We performed patch testing (n=21) for dental series and did lymphocyte transformation test (n=18) for metals. We measured mercury in samples of blood (n=19), urine (n=19), saliva (n=20), and scalp hair (n=17) to investigate the association between mercury levels and cases of MCS.Results. The prevalence of metal immune hypersensitivity in a subset of 26 patients was 92.3 percent. Elevations of mercury occurred in 81.2 percent (26 of 32). The mean (±SD) in blood concentrations of mercury was7.6±13.6 μg/L; mean in urine was1.9±2.5 μg/L; mean in scalp hair was2.2±2.5 μg/g; mean in saliva was38.1±52.1 μg/L. Subgroup analyses showed that elevation of mercury levels in biological matrices were associated with mercury amalgams in patients with MCS (22 patients), compared with controls (8 patients) (odds ratio 11 : 95 percent confidence interval 1.5 to 81.6;P=0.023).Conclusions. Our data show an increased prevalence of metal allergy and elevation of mercury levels in bioindicators among patients with MCS.