Multiple Chemical Sensitivity (MCS)

From food additives, perfume ingredients, fabrics, paints, petrol, detergents and fire retardants.



Multiple Chemical Sensitivity triggers

Every day people in the industrialised world come in contact with many chemicals.  These may be in foods, such as artificial flavourings, colourings or preservatives, or various items used in perfumes, fabrics, paints, petrol, detergents, fire retardants in furniture and so on.  In liquid form these are known as hydrocarbons. Their emissions are known as volatile organic compounds which suggests an ability to change and become unstable depending on conditions of temperature or humidity.  Fertilisers and pesticides, which are used to promote growth and protect food from contamination, have similar properties.  All originate from chemicals known as organophosphates.  Occasional exposure to these chemicals is unlikely to cause major symptoms of toxicity e.g. breathing problems, lethargy, generalised muscle aching, confusion or collapse but could do if the exposure is heavy and prolonged.  However, a few individuals with low tolerance can develop the same symptoms if they come in contact with sub-toxic levels of these chemicals.  This phenomenon is described as Multiple Chemical Sensitivity (MSC).

Before visiting the allergy centre my allergy to woodsmoke and most things perfumed controlled my life. I had to leave restaurants if they had a log fire, I had to ask friends not to wear perfume when visiting me.  I am now receiving treatment for these allergies and have been symptom free for nearly a year.  S. H-G Tring

How does MCS happen?

It is unusual to see in our clinics a person with MCS who does not have a history of allergy to natural inhalants such as dust mites, pollens, animals or moulds or long standing food intolerance, see section on Food Intolerance.  Therefore, MCS is an alarming development in a long chain of events which previously overloaded one's immune system.  It is important to emphasise that most conditions caused by these allergenic factors do not usually receive cause-oriented medical care and doctors, in an attempt to alleviate the problem, resort to a suppression of the symptom without realising the complex immune mechanisms in operation.

Predisposing Factors & Mechanisms

Frequent contact with chemical agents is likely to sensitise a person.  Example: contact dermatitis can start affecting a person's hands after years of safely using washing up liquid; clerical staff can become unwell when close to photocopiers; ordinary people can become hypersensitive to other people's perfumes, hair sprays, deodorants or smoking; drivers, previously oblivious to any symptoms from traffic fumes, can become sensitive to petrol and exhaust fumes.  It is possible that people with chemical sensitivity have a genetic predisposition affecting important detoxification processes in the cell.  The human nose is capable of recognising a scent in the air in concentrations as little as 1:500,000,000 parts.  Patients and their families often think of chemical sensitivity as a life-threatening allergy because of the severity and the speed of the symptoms they experience.  However when tested for markers of immediate allergy to these chemicals, this is not confirmed. Different mechanisms are in operation here, such as T-lymphocytes, cellular hormones and immunoglobulin-G all of which are capable of causing serious symptoms, mimicking allergy.

Effects and Symptoms

Chemical sensitivity is not a mere dislike of a smell or a chemical in the air, it is the fact that a person feels unwell or ill, suffers with sudden debilitating weakness, lethargy, nasal congestion, headache, muscle aching, confusion, brain-fog, nausea, perspiration, acute anxiety, panic attacks or acute depression and sometimes collapse. In MCS the physical suffering is sometimes interwoven with a strong psychological component: in an attempt to minimise contact with other people's perfumes and environmental pollutants some patients are forced to live in a reclusive environment and socialising becomes problematic.   From a psychiatric angle these syndromes are akin to some psychiatric diagnoses such as obsessive-compulsive disorder, acute anxiety states or phobias and even schizophrenia. Whilst it is important to identify and address the underlying cause(s), it is sometimes difficult to ignore the strong psychological component which exists and might hinder effective help with this condition.

Sick Building Syndrome

Several years ago, a number of clerical staff whose firms started operating from new premises, became unwell complaining of a variety of vague symptoms; they felt better when they went on leave or during the weekends.  After the initial scepticism it became obvious that their symptoms were the result of chemical emissions from new carpets, wall paints and plastics, to which some employees reacted more seriously than others, combined with poor ventilation. The same workers experienced no symptoms when they were asked to work in different premises.  A similar situation occurred in recent years when some passengers and aircrew on longhaul flights became nauseous and suffered breathing difficulties from the effects of legal levels of aviation fuel emissions in the passenger cabin.  Chemical sensitivity may be affected by constant contact with high electromagnetic frequencies (EMF) generated by modern electrical appliances, laptops, wi-fi, mobile telephones and so on.

Treatment for Multiple Chemical Sensitivity

Chemical sensitivity can be confirmed with a placebo-controlled challenge.   In a clean, thoroughly purified setting the administration of sublingual drops for a number of chemicals causes transient symptoms, whereas water or normal saline solution does not. The diagnosis of Multiple Chemical Sensitivity relies on one's detailed history and specific tests. Lymphocyte sensitivity to most chemicals including mercury, nickel, silver, all present in dental fillings and fat cell biopsy are also useful investigations in assessing the extent and severity of the problem. When one cannot avoid any of these factors it is possible to improve tolerance using a safe and specific method of desensitisation.  See Neutralisation.

You may be interested to listen to this Radio 4 Programme "Allergic to the 21st Century  which was presented on the 31st March 2015.

Allergic to the 21st Century

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Specialist tips and notes

  1. Your home is the only place you can truly control and where you spend at least one third of your daily life. It is worthwhile making it a safe-haven by removing all sources of chemical emissions. Containers of perfumes, hair sprays, deodorants and most cosmetics and toiletries may be tightly closed but they still allow some emissions to escape slowly.
  2. Paints, detergents, spray polishes, air-fresheners can be removed from the main house and be placed in a plastic container left outside the house or in the garage. There is an extensive range of user-friendly alternatives available today containing natural, less reactive substances.
  3. Ventilate your home well, unless you live near heavy traffic; invest in an inexpensive HEPA or carbon filter, which are effective in removing most of these dangerous chemicals from the air. Check your gas boiler to ensure that any gas emissions are directed outside, most new ones manufactured in recent years should be safe.
  4. If you have had dental amalgams for years and tests have confirmed sensitivity or toxicity to any of their metals, consider and discuss with your dentist the possibility of having them removed and replaced with white, composite fillings.
  5. The Disability Discrimination Act and recent progress in adopting a proactive approach with the 1998 Act of Human Rights, have assisted in making many companies and employers more flexible toward employees problems arising from conditions in the place of work. For instance, some of our clients have been able to work in a smaller office, free of other people's perfumes or away from photocopiers/toners, emitting glutaraldehyde. Others have been allowed to take their work home and avoid the office.
Dr Econs is one of the Medical Advisers to MCS Aware, a charity who offer a helpline and advice for those whose health is affected by chemical emissions in the environment.

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