Each of these random things can create an unpleasant physical symptom.

Does that mean the afflicted person has a

Chemically Sensitivity or an Allergy?

I’ve noticed the term chemical sensitivity is used rather than chemical allergy. To me this indicates that a “sensitivity” is somehow less valid or less intrusive to a person’s life than an “allergy.” If the two words are perceived differently does that mean the approach to treating each one is different? Does the information from one area not cross over in an informative way into the other? This perplexed me so I dug into it.

Photo from Flickr - D-Photography

How is an allergic reaction to touching rubber just a sensitivity when the rash is devastating? Photo from Flickr – D-Photography

First I looked into what the meaning of chemical sensitivity is. In the Cambridge Dictionary you can’t look up the two words together. However, sensitivity means – “the quality of being easily influenced, changed, or damaged, esp. by a physical activity or effect: the quality of needing to be treated with care or secrecy.” (a) In the same dictionary chemical means – “any basic substance that is used in or produced by a reaction involving changes to atoms or molecules: of, involved with, relating to, or made by using chemicals or chemistry.” (b) That wasn’t much help either considering everything – food, inorganic materials and people – are made of molecules all constructed of the same basic elements.  

I put the words back together and looked on WebMD I read a chemical sensitivity is “an immune response similar to allergies.” (c) The words “similar to allergies” jumped out at me because it indicates that chemical sensitivity and allergy are the same but different, so what does that mean. I don’t know about you but I don’t feel like I have made much headway in resolving this dilemma.

Peanuts are a common allergy. Or is it just a sensitivity? Photo from Flickr – www.Pixel.la

On the Chemical Sensitivity Foundation website I read chemical sensitivity is “a medical condition characterized by debilitating chemical sensitivities. People who are chemically sensitive are made sick by exposures to chemicals found in many common products…these chemicals will make everyone sick at high levels, but for chemically sensitive people exposures to even small amounts of these substances can cause symptoms.” (d) First of all, that was written in plain English and I appreciate that. This definition seems to highlight, the similarity, that people with allergies also have reactions to small amounts of the chemicals they are allergic to.

 Still puzzled I went to Wikipedia which stated that a chemical sensitivity “is a complex chronic condition which manifests as a result of low-level exposures to certain everyday chemicals…hyperactive limbic system and autonomic nervous system were confirmed features of the condition…the evidence suggests organic abnormalities in sensory processing pathways and the limbic system…symptoms are typically vague and non-specific.” (e) If you ask me the meaning behind chemical sensitivity is still vague and non-specific. 

Perhaps diving into the meaning of allergy will help. The Cambridge Dictionary states an allergy is “a condition that causes illness when someone eats certain foods or touches or breathes in certain substances.” (f) Still not getting the difference.

Bee venom is a common allergy. Isn’t the venom just a chemical? It’s certainly not a virus. Photo of one of Nancy’s scratchboard creations

Back to WebMD. “Your immune system’s job is to protect you from bacteria and viruses. If you have allergies, though, part of your immune system works too hard. It may attack harmless substances…When your body meets an allergen, it makes chemicals called IgE antibodies. They cause the release of chemicals like histamine, which cause swelling and inflammation…as your body tries to remove the allergen.” (g) Here the reference to bacteria and viruses are confusing when allergens, like cat dander and pollen, are not bacteria or a virus. I am finding that an immune response seems to be a theme that runs through both terms chemical sensitivity and allergy.

According to Wikipedia and allergy is “a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment… These diseases include hay fever, food allergies, atopic [caused by an allergy that can affect any part of the body, not just the part that touches the thing that causes the allergy]dermatitis, allergic asthma, and anaphylaxis.” (h) There is the immune system mentioned again.

An every day item like elastic in clothing is an allergen for me. Or is that just a sensitivity? Photo from Flickr – Kelly

In the Australasian Society of Clinical Immunology and Allergy information, which was the easiest to read, I found, “Allergy occurs when a person’s immune system reacts to substances in the environment that are harmless for most people. These substances are known as allergens and are found in dust mites, pets, pollen, insects, ticks, molds, foods and some medicines.” (i) I find it curious they didn’t mention chemicals, even though many medicines are derived from chemicals.

Still feeling a bit confused I looked up the word sensitivity for its meaning. Merriam Webster dictionary defines it as “the quality or condition of being sensitive, the capacity of an organism or sense organ to respond to stimulation.” (j) Even though I feel like there are puzzle pieces missing yet, this is what I glean from my research. A chemical sensitivity is a medical condition where people get sick as a result of being exposed to chemicals. An allergy is an immune systems response, or an illness, to the introduction of a substance the body deems harmful. Both terms are based on chemicals in the body that illicit an immune system response resulting in compromising a person’s health.

To me both terms, chemical sensitivity and chemical allergy, appear to be the same thing and both equally valid. The approach to treating them should be equally robust. It appears the information gleaned for chemical sensitivities applies to allergies and visa versa. It is probably happening out there and I just haven’t found it yet. 

If you can shed light on this subject for us laymen please do.


 (a) https://dictionary.cambridge.org/us/dictionary/english/sensitivity

 (b) https://dictionary.cambridge.org/us/dictionary/english/chemical

 (c) https://www.webmd.com/allergies/multiple-chemical-sensitivity#1

 (d) http://www.chemicalsensitivityfoundation.org/pdf/Multiple-Chemical-Sensitivities-Brochure.pdf

 (e) https://en.wikipedia.org/wiki/Multiple_chemical_sensitivity

 (f) https://dictionary.cambridge.org/us/dictionary/english/allergy

 (g) https://www.webmd.com/asthma/qa/what-is-an-allergy

 (h) https://en.wikipedia.org/wiki/Allergy 

 (i) https://www.allergy.org.au/patients/about-allergy/what-is-allergy

 (j) https://www.merriam-webster.com/dictionary/sensitivity