Multiple chemical sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersen-sitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psy-chosocial influences. The development of MCS may be attributed to the sensitization of transient receptor po-tential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

Automated summary

Multiple chemical sensitivity (MCS) is a complex medical condition characterized by diverse features and common comorbidities associated with low dose chemical exposures. The development of MCS is linked to genetic influences, gene-environment interactions, oxidative stress, inflammation, cell dysfunction, and psychosocial influences. Sensitization of TRP receptors, particularly TRPV1 and TRPA1, is implicated in the pathogenesis of MCS. Misunderstanding of MCS as solely psychological in nature has resulted in stigmatization of patients and denial of their disability accommodation. Evidence-based education, as well as recognition of receptor-mediated biological mechanisms, is crucial for appropriate support and advocacy for MCS patients.