Idiopathic environmental intolerances (formerly multiple chemical sensitivity) psychiatric perspectives

Abstract

Idiopathic environmental intolerances (IEI)/multiple chemical sensitivity (MCS) is characterized by various somatic symptoms which cannot be explained organically, but are attributed to the influences of toxic environmental chemicals in low, usually harmless doses. In the absence of a widely accepted definition of IEI, contradictory aetiological hypotheses and therapeutic suggestions are discussed. Some authors doubt the existence of IEI/MCS as a disease entity of its own. The label IEI does not implicate neither a diagnosis of somatic disease nor that it is caused by an avoidable exposure. Many IEI patients suffer from psychiatric diseases. A majority of them can be diagnosed as somatoform disorders. Consequently, psychiatric therapies could be effective. This review describes the current knowledge about IEI/MCS, outlines a diagnostic algorithm and a psychotherapeutic concept for variants of IEI understood as a somatoform disorder.

The Search for Reliable Biomarkers of Disease in Multiple Chemical Sensitivity and Other Environmental Intolerances

“…Availability of data concerning the involvement of chronic oxidative and nitrosative damage in the induction and perpetuating of symptoms in different environmental hyper-sensitivity syndromes has been growing in the last decade (for detailed review, see [3,20,124]). Abnormal oxidative stress levels were first reported in FCS patients by Jammes et al [125], demonstrating increased TBARS levels and ascorbic acid consumption in response to incremental exercise, and by Kennedy et al [126], reporting high plasma isoprostane and oxidised LDL levels in obese and nonobese FCS patients.…”

“…Therefore, different environment-associated multi-organ conditions, in most cases still lacking a consensus on clinical case definition, such as multiple chemical sensitivity (MCS), fibromyalgia (FM), chronic fatigue syndrome (CFS), sick building syndrome (SBS), hypersensitivity to electro-magnetic fields (EHS), and others, in most cases still lacking a consensus on clinical case definition, have been subjected in the last decade to clinical and laboratory studies [3]. These are aimed at proving any possible organic cause, or oppositely the psychogenic etiology, as proposed by part of the clinicians on the basis of the prevalent neurologic impairment [3,4].…”

“…Therefore, different environment-associated multi-organ conditions, in most cases still lacking a consensus on clinical case definition, such as multiple chemical sensitivity (MCS), fibromyalgia (FM), chronic fatigue syndrome (CFS), sick building syndrome (SBS), hypersensitivity to electro-magnetic fields (EHS), and others, in most cases still lacking a consensus on clinical case definition, have been subjected in the last decade to clinical and laboratory studies [3]. These are aimed at proving any possible organic cause, or oppositely the psychogenic etiology, as proposed by part of the clinicians on the basis of the prevalent neurologic impairment [3,4]. Main difficulties towards a clinical consensus on disease classification lie in: (i) the wide array of symptoms and signs allegedly linkable to environmental triggers exposure, (ii) the diversity of the subjects affected, reacting on the basis of individual sensitivity and possibly genetic predisposition, (iii) the mere absence of proven pathogenic mechanisms and consequently of clear-cut diagnostic criteria, (iv) the wide spectrum of possible triggers [2] and the absence of clear dose-dependent reactions, generating methodological difficulties and bias in provocation studies.…”

“…On this basis, the World Health Organization has initially defined this group of invalidating conditions as “idiopathic environmental intolerances” (IEI) [5], with special reference to MCS. Awaiting for adequate mechanism elucidation, these complex and chronic conditions have then also been appointed with a second collective discouraging label of “medically unexplained symptoms” [3,6]. …”

“…Indeed, the question as to whether SRI should be considered diseases or plain clusters of symptoms remains unanswered by available conventional clinical interpretations of acute/chronic inflammatory processes [3,28], since patients only partly display recognized dysfunctions of the immune system, or IgE-based allergic reactions, or any detectable anatomic or functional organ alteration unequivocally connected with trigger challenge.…”