Idiopathic Environmental Intolerance
(IEI) is an acquired disorder with multiple recurrent symptoms, which is associated with diverse environmental factors that are tolerated by the majority of people.
(1,2) Experts have advocated many terms for the resulting illness (Table 1), and in 1996 a World Health Organization workshop recommended adopting the term Idiopathic Environmental Intolerance
to denote the substantial overlap between these labels.
Receptor typing for cholecystokinin--a known panic-causing neuropeptide--showed that 11 subjects with idiopathic environmental intolerance
had a greater prevalence of cholecystokinin-B receptor allele 7 (41%), compared with 11 matched controls (9%).
Multiple chemical sensitivities (MCS) syndrome, also known as idiopathic environmental intolerance
, is a controversial diagnosis that encompasses a wide range of waxing and waning, subjective symptoms referable to more than one body system and provoked by exposure to low levels of chemicals, foods, or other agents in the environment.
MCS is also known as "the 20th century disease," "chemically acquired immunodeficiency syndrome," "total allergy syndrome," and "idiopathic environmental intolerances
" (American Academy of Allergy, Asthma and Immunology Board of Directors 1999; Graveling et al.
Other names include "chemical hypersensitivity," "environmental hypersensitivity," "total allergy syndrome," "cerebral allergy," "chemical AIDS," and "20th Century Disease." In February a World Health Organization (WHO) workshop in Berlin concluded that MCS should be called "idiopathic environmental intolerances
," with idiopathic defined as "self-originated" or "of unknown causation."