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Discriminating between organic and psychological determinants of multiple chemical sensitivity: A case study

2008; Taylor & Francis; Volume: 14; Issue: 6 Linguagem: Inglês

10.1080/13554790802498948

1465-3656

Gesualdo M. Zucco, Carmelo Militello, Richard L. Doty,

Fibromyalgia and Chronic Fatigue Syndrome Research

Abstract Multiple chemical sensitivity (MCS) is a controversial disorder characterized by a diverse set of debilitating symptoms purportedly induced by environmental chemicals. Many cases of putative MCS are believed to have a strong psychogenic component, making it difficult to differentiate between organic and psychogenic causes. In this case report we describe a procedure that can aid in this differentiation. A patient who met a strict set of criteria for MCS was tested on two test occasions. On the first, the patient was found to have no olfactory dysfunction, as determined from standardized olfactory tests. On the second, odorants, as well as a blank stimulus, were presented to the patient with instructions as to whether they were harmful or harmless. The patient's task was to estimate the intensity of each odorant and report any induced MCS-related symptoms. Potentially harmful odorants presented as harmless were judged significantly less intense, and triggered fewer symptoms, than harmless odorants presented as harmful. When an odorless stimulus was presented as harmful, the patient provided higher intensity evaluations and exhibited more symptoms than when it was presented as harmless. These phenomena were not present in three non-MCS controls. This straight-forward procedure allowed us to determine that the MCS symptoms of this patient were largely psychological and may be of general value for identifying psychogenic cases of MCS. Keywords: Multiple chemical sensitivityOlfactory testsAssessmentCase studyOrganic and psychological etiologies The authors wish to thank Professor R. Job for comments and criticism on an early draft, Dr R. Casadei for his help in collecting the data, and Dr A. Bobbio for technical support. The authors are particularly grateful to Mrs C.F. Notes Zucco, G., & Hummel, T. (unpulished test, 2007). Sniffin' Sticks: Olfactory performance assessed by a new odor recognition test. Reliability and normative data.