Patients with multiple chemical sensitivities (MCS) often report heightened sensitivity to odors. Odor detection thresholds to phenyl ethyl alcohol (PEA) and pyridine (PYR) were evaluated as a measure of odor sensitivity for 33 MCS subjects, 13 chronic fatigue syndrome subjects, 16 asthmatic subjects, and 27 healthy controls. Odor identification ability (based on University of Pennsylvania Smell Identification Test results) and ratings in response to four suprathreshold levels of PEA and PYR were also assessed. Odor detection thresholds for PEA and PYR and odor identification ability were equivalent for all groups; however, when exposed to suprathreshold concentrations of PEA, MCS subjects reported significantly more trigeminal symptoms and lower esthetic ratings of PEA. No group differences were found in response to suprathreshold concentrations of PYR. In summary, MCS subjects did not demonstrate lower olfactory threshold sensitivity or enhanced ability to identify odors accurately. Furthermore, they were differentiated from the other groups in their symptomatic and esthetic ratings of PEA, but not PYR.
From the University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Environmental and Occupational Health Sciences Institute, Piscataway (Dr Caccappolo, Ms Kelly-McNeil, Dr Hamer, Dr Kipen, Dr Fiedler); the Center for Environmental Hazards Research, DVAMC, East Orange, and the Department of Neurosciences, UMDNJ–New Jersey Medical School, West Orange (Dr Natelson); and Unilever Research, Edgewater, N.J. (Dr Knasko).
Address correspondence to: Nancy Fiedler, PhD, UMDNJ, Robert Wood Johnson Medical School, EOHSI, 170 Frelinghuysen Road, Piscataway, NJ 08854.