Idiopathic environmental intolerances (IEI) - Formerly multiple chemical sensitivities (MCS) - Psychiatric perspectives

The term "idiopathic environmental intolerances" (IEI)/"multiple chemical s ensitivities" (MCS) is used to describe a complex of heterogeneous somatic symptoms without a diagnoseable organic disease. Symptoms are believed to b e triggered by exposure to tow levels of environmental chemicals that are u sually well tolerated by the general population. There is no widely accepte d definition for the phenomenon. A number of contradictory etiologic hypoth eses and therapeutic concepts are discussed. One of the crucial questions i s whether IEI/MCS should be understood as an own entity of disease. It has been demonstrated that a majority of patients with IEI/MCS meet diagnostic criteria for psychiatric diseases. Most frequently, somatoform, affective a nd anxiety disorders can be diagnosed. Therefore, psychiatric and psychothe rapeutic therapy seems appropriate. The present paper provides a review of the different case definitions, etiologic and therapeutic concepts and of s tudies examining the frequency of psychiatric morbidity in patients with IE I/MCS, Additionally, a diagnostic algorithm and a concept of behavioral the rapy for IEI/MCS patients with somatoform disorders are described.