What are several chemical sensitivities

MCS syndrome

MCS syndrome (Multiple chemical sensitivity, multiple chemical intolerance, multiple chemical hypersensitivity, idiopathic environmental intolerance): The causal picture is unclear with a variety of complaints, which those affected attribute to harmful substances such as solvents, exhaust gases, cigarette smoke or fragrances in the environment. Women are affected significantly more often than men.

Leading complaints

  • Fatigue, exhaustion, weakness
  • Headache and pain in the limbs
  • Circulatory problems, e.g. B. Dizziness
  • nausea
  • High odor sensitivity to certain chemicals, possibly also harmless substances
  • The chronic stressful situation, when those affected cannot avoid the triggering substances in everyday life, leads to states of exhaustion with sleep and concentration disorders, burning eyes, dizziness, shortness of breath, complaints of the musculoskeletal system, gastrointestinal problems, pain, itching or inflammation of the skin and mucous membranes .

The illness

Those affected chronically suffer from complaints that they and / or their doctors attribute to environmental chemicals (especially volatile substances, e.g. in solvents such as formaldehyde from plastics or paints), heavy metals (e.g. amalgam fillings), food additives, Candida colonization of the intestine or electromagnetic fields . Around a fifth of those affected indicate more than ten complaint-causing substances. The level of suffering is high and often leads to permanent incapacity for work.

In spite of several studies and increasing public interest, there is little reliable knowledge about the causes of MCS syndrome. All statements about the causes of MCS can tend to be assigned to one or more of the following three basic factors:

  • Exposure theory. An increased exposure to one or more pollutants (initial exposure), which subsequently grows over the years into hypersensitivity to (many) other substances.
  • Vulnerability theory. An increased risk for MCS, which researchers suspect especially in other pre-existing chronic diseases. These include an allergic disposition, hypersensitivity to stress, depression, anxiety disorders and post-traumatic stress disorders. The fact that women are more frequently affected by this than men explains their significantly higher incidence of MCS compared to men.
  • Psychosomatic disorder. Many medical professionals see MCS as an expression of a somatoform disorder. This thesis is increasingly being questioned today; MCS self-help organizations, for example, interpret the psychological abnormalities often observed in MCS sufferers as a consequence of MCS, not as a cause. However, it is undisputed that there is a pronounced psychosomatic comorbidity of MCS with diseases such as chronic fatigue syndrome.

The doctor does that

The diagnosis of other diseases is the top priority, such as allergies. Which examinations are useful depends on the complaints of the person concerned.

If no other treatable diseases can be identified, the therapy is based on three pillars:

  • Eliminate harmful environmental influences as consistently as possible (at least within the patient's own four walls).
  • Supportive psychotherapeutic therapeutic approaches for coping with the often extremely stressful life situation of those affected.
  • Comprehensive information transfer about the clinical picture.

Psychotropic drugs tend to be contraindicated. Psychotherapy alone also tends to be ineffective. The prognosis for MCS is poor.


Dr. med. Arne Schäffler, Dr. med. Nicole Menche in: Health Today, edited by Dr. med. Arne Schäffler. Trias, Stuttgart, 3rd edition (2014). Revision and update: Dr. med. Sonja Kempinski | last changed on at 16:06

Important note: This article has been written according to scientific standards and has been checked by medical professionals. The information communicated in this article can in no way replace professional advice in your pharmacy. The content cannot and must not be used to make independent diagnoses or to start therapy.