Safety Considerations and Factors to Consider Regarding Allergies and Essential Oils: Part II










In Part I of this article series, I discussed the importance of safety considerations regarding usage and applications of essential oils. Being mindful of these factors is paramount for an essential oil lover to achieve the desired benefits and prevent unwanted side effects. (Please see my essential oils database, under the category “Children & Safety” and “Essential Oils and Carrier Oils,” to learn more on safe use of essential oils.)

I also provided an overview of the four categories of allergic, or hypersensitivity, reactions. Of the four types, it has been stated that essential oils have only been involved in type IV, delayed hypersensitivity reactions. This is related to their constituents being classified as haptens. This means essential oils are not antigenic themselves, but can attach to proteins or other allergic molecules, contributing to an allergic response over time.

Finally, I began the description of “skin sensitization.” Specifically, I noted that is important for essential oils to be rotated and for one not be “heavy-handed” when applying them to prevent this. In my fifteen years with essential oils, I have rarely seen this. In the few that have reported sensitization, it was in my “sensitive type” clients prone to skin reactions. (There are more factors below.)

You can read the full discussion of the above in Part I here.

Now that I’ve “primed” your interest, I will expand on these points and discuss additional caveats, factors, considerations, and predispositions that would make one more prone to a reaction to essential oils.

Here goes…


Considerations in Sensitization and Allergic Responses:







(1) The Terpene Factor

Here’s an important point. When cross-referencing Lindsey Elmore, the “essential oils farmacist,” I found an article that stated it was the synthetic and OXIDIZED terpenes that were linked to contact dermatitis (an allergic skin response) versus pure terpenes. This 2008 article in Chemical Research in Toxicology stated:

Oxidized fragrance terpenes, in contrast to the pure terpenes, gave positive patch test reactions in consecutive dermatitis patients as frequently as the most common standard allergens. This shows the importance of using compounds to which people are exposed when screening for ACD in dermatology clinics.

I then found this abstract, which again highlighted the complex response that occurred in dermatitis patients:

Terpenes are widely used fragrance compounds in fine fragrances, but also in domestic and occupational products. Terpenes oxidize easily due to autoxidation on air exposure. Previous studies have shown that limonene, linalool and caryophyllene are not allergenic themselves but readily form allergenic products on air-exposure. This study aimed to determine the frequency and characteristics of allergic reactions to selected oxidized fragrance terpenes other than limonene. In total 1511 consecutive dermatitis patients in 6 European dermatology centres were patch tested with oxidized fragrance terpenes and some oxidation fractions and compounds. Oxidized linalool and its hydroperoxide fraction were found to be common contact allergens. Of the patients tested, 1.3% showed a positive reaction to oxidized linalool and 1.1% to the hydroperoxide fraction. About 0.5% of the patients reacted to oxidized caryophyllene whereas 1 patient reacted to oxidized myrcene. Of the patients reacting to the oxidized terpenes, 58% had fragrance-related contact allergy and/or a positive history for adverse reaction to fragrances. Autoxidation of fragrance terpenes contributes greatly to fragrance allergy, which emphasizes the need of testing with compounds that patients are actually exposed to and not only with the ingredients originally applied in commercial formulations.

Therefore, this shows that the terpenes contribute to an allergic response WHEN (1) there’s been oxidation of terpenes (2) in allergenic fragrance products (3) when exposed to air and (4) in those already sensitized.

Please ensure your essential oils company to not use synthetic fragrances in their products! This brings us to number 2…


(2) The Toxic-Moisturizer Effect

There’s another big factor that I’ve found common in my clients regarding a skin sensitization response:
Essential oils can act as efficient delivery vehicles of various substances.

This means that skin application of essential oils “drives in” other lipid-soluble substances and compounds (including unwanted chemicals) into the skin.

Some people may not be aware that their “favorite brand of skin moisturizer contains harmful chemicals that could react with the essential oil (perhaps oxidizing terpenes with those fake fragrances?). This could potentially be triggering a heightened risk for a sensitivity response!

If this is the case, and for your overall health, using a moisturizer that is non-toxic as a carrier oil for the essential oil is important.

Here are some articles with resources for non-toxic personal care products: Article 1, Article 2, Article 3, Skin Deep Database.


(3) Skin Aging

As the skin ages and breakdowns, certain areas could theoretically become more “sensitized” and vulnerable to skin irritation.

For this reason, many people do well to dilute and test their essentials oils using the “skin patch test method.” Basically, you “test” a drop of the oil to a small area on the forearm and observe the skin response before slathering it all over your body.

This website lists some essential oils that have been more commonly involved to sensitization.


(4) Photosensitization


I have experienced the unpleasant effect of this sensitization reaction. It occurred between the intense Tuscan sun and the citrus essential oils, which were high furanocoumarins, slathered on my skin. This summer day, on the lovely beaches of Italy, a spectacle of a fair-skinned woman turning into a cooked lobster was witnessed by many Italians!  Therefore, regardless of temperature, last year was not “short season” for this ivory-toned lady!


Table 3 and 4 here list some common oils categorized as photosensitizers that you should review before heading to any beach!



Finally, Respect the Protein Argument and Let’s Not Be So Divided

Technically, it is believed that it is proteins that cause allergies. This has led many to argue that essential oils can’t cause allergies while others vehemently argue negative responses do occur. This technicality has caused more division and argument (as if we needed more) among the different schools of aromatherapists. Therefore, let’s show our respect to clinicians, scientists, and fellow oil lovers who use terminology concisely for accurate diagnosing and safety instructions.

Here is my summary in regard to allergies and essential oils:

“Essential oils may potentially contribute and trigger delayed allergic responses. This is mostly related to skin hypersensitivity and occurs due to their constituents being haptens. We must consider proper dosage, application, purity of the oils, and the sensitivity of the individual in relationship to this response.”

Please note this last important point:

Allergic responses occur if someone’s immune system “primed” to overrespond to a trigger.

If you have an allergy to anything, the underlying predispositions, triggers, and mediators should be explored and addressed if you’d like to find lasting relief.

In an upcoming article these contributors to why someone would have an allergic response to essential oils, and in general, to begin with will be explored. I discussed a little about this here, but I’ll go into much greater detail. So, stay tuned!


Wait, Dr. Sarah! I Wanted to Hear About the Eucalyptus response?!

Okay, I won’t end yet!!

I will touch on the “eucalyptus and asthma exacerbation” question that I receive at times.

Specifically, some worry that using this essential oil may ignite an asthma attack, especially in children.

Interestingly, its major constituent, 1,8-cineole, is known for soothing spasms and overactive immune responses. I wrote more about eucalyptus here.

With these claims, as far as I know, the over-dosage effect may have been at play.

That’s All Folks

In the meantime, we can rest assured that with proper use and knowledge we can avoid unwanted side effects and enjoy our oils for years to come!



Disclaimer: This information is applicable ONLY for therapeutic quality essential oils. This information DOES NOT apply to essential oils that have not been tested for purity and standardized constituents. There is no quality control in the United States, and oils labeled as “100% pure” need only to contain 5% of the actual oil. The rest of the bottle can be filled with fillers and sometimes toxic ingredients that can irritate the skin. These studies are not specific for any essential oils brand or company, please consult the source.

This material is for information purposes only and is not intended to diagnose, treat, or prescribe for any illness. You should check with your doctor regarding implementing any new strategies into your wellness regime. These statements have not been evaluated by the FDA.