Multiple chemical sensitivity is an entity that is still discussed by medicine, which consists of the appearance of specific symptoms when the affected person is exposed to environmental stimuli considered innocuous.

Multiple chemical sensitivity (MCS), also called idiopathic environmental intolerance, is a syndrome in which central sensitization. When exposed to doses considered well below toxic, usually to various types of environmental stimuli – chemical or not, a wide variety of symptoms occur that typically disappear, but not always when the stimulus ceases.

The criteria to consider that a person has multiple chemical sensitivity are:

• It is a chronic pathology.
• The manifestations reappear with each new exposure to the agent.
• Symptoms are experienced with directions of very low intensity or concentration.
• The images of sensitivity diminish or disappear when the stimulus that triggered them is interrupted.
• The same reaction occurs when you are exposed to different products, which are not related to each other.
• Symptoms affect various systems and systems of the body.

MCS, which has only been described in developed countries, is much more frequent in women, usually beginning between 30 and 50. Interestingly, single people have MCS much less frequently than married people. In a US study, Hispanics were more likely to be diagnosed with multiple chemical sensitivity. The level of education, employment, and income do not seem to influence the appearance of this problem.

Multiple chemical sensitivity has uneven recognition as a nosological entity by various organizations and nations. The WHO does not recognize it as a disease, nor does the American Medical Association. However, in Spain, for example, MCS entered the international classification of diseases (the ICD) in January 2014, so it has its entity today.

Not many studies have been done to find out what percentage of the population is affected. In a German study, 9% of the population claimed to have chemical sensitivity, and 0.5% had a medical diagnosis of MCS. In some studies carried out in the USA, 13 to 33% of chemical sensitivity rates have been found, with a medical diagnosis of MCS in 3-6% of the population.

Causes of multiple chemical sensitivity

The multiple chemical sensitivity (MCS), like fibromyalgia or chronic fatigue syndrome, could encompass central sensitization within syndromes. It is considered that there is hyperexcitability of the central nervous system and the immune system that generates symptoms of various types, exaggerated in the intensity of the kind of stimulus that initiated them, and that often persist over time despite the disappearance of the inspiration.

It cannot be said that there is a single cause that by itself can produce the symptoms of multiple chemical sensitivity. Combining factors that can produce a condition that is considered compatible with this diagnosis are genetic and epigenetic (environmental factors that influence gene expression in a few generations without consisting of mutations) and ecological.

Regarding genetics, much remains to be investigated. It has already been seen, for example, that there are polymorphisms related to enzymes that metabolize various substances such as cytochrome P450 reductase, glutathione-S-transferase, N-acetyltransferase, or superoxide dismutase. Also, there are variants of nitric oxide synthase that are related to MCS.

However, predisposing genetics alone does not produce a chemical sensitivity. Epigenetic factors such as maternal or grandmother’s exposure to certain toxins (including tobacco), or even maternal psychosocial stress during pregnancy, can influence the programming of the fetus’ neuroendocrine stress axes, determining a certain predisposition to MCS. Likewise, abuse or adverse experiences in childhood (in the first 18 years of life) influence this programming.

Finally, multiple chemical sensitivity is an entity that is currently known exclusively in developed countries. The Western lifestyle indicates that the environment, with pro-inflammatory nutrition, with little implantation of breastfeeding, a significant alteration of the microbiota, and a type of psychosocial stress for which we are not prepared, can end up triggering. The symptoms of MCS by pathophysiological mechanisms are not fully known, but in which neurophysiological and neuroimmunoendocrine alterations have been implicated.

Avoid products that contain toxic chemicals:

EDCs are exogenous chemicals that interfere with hormone action, thereby increasing the risk of adverse health outcomes, including cancer, reproductive impairment, cognitive deficits, and obesity.

These are often used in children and household products. Research shows that even very low-dose exposure to BPA and other plasticizers can be detrimental to fertility and reproduction. It’s a good idea to use BPA and phthalate free products to preserve your healthier lifestyle and protect young ones.