Idiopathic Environmental Intolerances

The constellation of symptoms that has come to be known as multiple chemical sensitivities or idiopathic environmental intolerance is increasingly recognized, although the definition is elusive and its pathogenesis as a distinct entity is unconfirmed. The mechanisms that have been proposed include altered immune function, neurogenic inflammation, neurologic sensitization, and conditioned reflexes and genetic differences in drug metabolism enzymes or factors involved in the generation or response to oxidative stress. To date, no chemically related mechanism has been established.