Université Paris Descartes AP-HP Service de pathologie professionnelle Groupe hospitalier Cochin 27, rue du faubourg Saint Jacques 75014 Paris France
“Idiopathic environmental intolerance” has become the universally accepted terminology for a syndrome that has been referred to by various names, the most common of which was “multiple chemical sensitivity”. This syndrome frequently but not necessarily links a highly varied collection of symptoms with an olfactory perception in the general or occupational environment of chemicals considered noxious by patients. This ailment is mainly studied in Western countries, where its prevalence varies quite substantially. Numerous and diverse etiopathogenic theories have been proposed, some suggesting a toxic cause (immunotoxic or neurotoxic mechanisms, etc.), others suggesting a psychopathological origin akin to those of psychosomatic diseases. Whatever the cause, this syndrome has highly negative repercussions on patients' personal and professional lives. This impact can be reduced through a medical approach that takes the patient's complaints into account, limits additional testing and workups to what is necessary to rule out other diagnoses, and aims at striking the best possible balance between banning suspected chemicals and preserving occupational and social activities.