Aromatherapy as an adjuvant treatment in cancer care--a descriptive systematic review.
Repeated topical administration of lavender and tea tree oil was associated with reversible prepubertal gynecomastia.PubMed 23983386 ↗
Open Source Apothecary At Home / Safety
Essential oils: concentration, sensitisation and the things you must not do
An essential oil is a concentrated solvent. Most oil injuries are dilution errors, not allergies.
safetySteam distillation concentrates a plant's volatile fraction into a liquid that is chemically a solvent. Full-strength application is the single most common error, and it produces chemical burns and a permanent sensitisation rather than a harmless irritation.
Dilution is the whole discipline. A 2-3% dilution in a carrier oil is the normal range for adult skin and the range used in the topical trials that show an effect; neat application is reserved for a specific, small, deliberate use and never for a large area, a mucous membrane, or a child. Because plant and bottle strengths differ, dilution should be measured, not judged by drops-from-the-bottle intuition.
Sensitisation is permanent and cumulative. Repeated neat exposure to a known sensitiser can convert an occasional irritation into a lifelong allergy. Tea tree oil, lavender, and the citrus and cinnamon materials are the usual offenders.
Phototoxicity. Expressed citrus peel oils — bergamot, lime, lemon, and bitter orange, particularly cold-pressed rather than distilled — contain furanocoumarins. Applied to skin and then exposed to sun, they produce a phototoxic burn that can be severe and can leave pigment change for months. Bergamot is the classic. Distilled citrus oil has far less furanocoumarin, which is why the distinction matters and why "bergamot" on a label is not enough information.
Never:
- Never swallow essential oils except on a qualified practitioner's instruction for
- Never put undiluted oil in the ear, the eye, the nose, or on the genitals.
- Never use peppermint, camphor or eucalyptus oil on or near the face of an infant or
- Never leave a bottle open or within a child's reach. These are the commonest
- Never use citrus peel oil on skin that will be in sun.
What the studies found
Photocontact dermatitis.
The procedure as outlined in this manuscript is relatively simple and can easily be accomplished in the dermatologist's office.PubMed 15327473 ↗
[Sensitization to tea tree oil in Germany and Austria. A multicenter study of the German Contact Dermatitis Group].
Our results show that tea tree oil is an important contact allergen for some centers.PubMed 16296153 ↗
Psoralen-Induced Phytophotodermatitis.
This article focuses on the diagnosis and management of psoralen-induced phytophotodermatitis along with other clinical applications.PubMed 33273237 ↗
Allergic Contact Dermatitis to Fragrances.
In the proper clinical setting, supplemental patch testing with an additional fragrance or essential oil series should be considered.PubMed 32475515 ↗
Limonene Hydroperoxides.
It should be realized, however, that a number of "positive" reactions may well be false-positive, irritant responses.PubMed 31433385 ↗
Cautions and interactions
- Dilute to 2-3% for adult skin. A 2% dilution is about 12 drops per 30 mL (1 fl oz) of carrier oil — measure rather than pour.
- Do not use essential oils on infants or on the face of young children.
- Phototoxic citrus peel oils — do not apply to skin exposed to sunlight within 12-24 hours.
- Epilepsy, asthma, and pregnancy each make some oils a poor choice; check the specific oil rather than assuming a rule generalises.
When this is not a self-care problem — get help
- Essential oil swallowed, or oil in the eye, or a child who is drowsy, coughing or breathing badly after exposure — poison control and emergency care immediately. Keep the bottle to show them.
- A rash that spreads, blisters, or does not settle in days after applying an oil — that is a sensitisation, and re-exposure makes it worse.
Known interactions
- Topical methyl salicylate (wintergreen) is absorbed and interacts with warfarin; it is the classic unrecognised interaction in this group.
Related
Sources
- Aromatherapy as an adjuvant treatment in cancer care--a descriptive systematic review. African journal of traditional, complementary, and alternative medicines : AJTCAM 2012; doi:10.1002/14651858.CD002287.pub2 PubMed 23983386
- Photocontact dermatitis. Dermatologic therapy 2004; doi:10.1111/j.1396-0296.2004.04026.x PubMed 15327473
- [Sensitization to tea tree oil in Germany and Austria. A multicenter study of the German Contact Dermatitis Group]. Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG 2003; doi:10.1046/j.1610-0387.2003.03727.x PubMed 16296153
- Psoralen-Induced Phytophotodermatitis. Dermatitis : contact, atopic, occupational, drug 2021; doi:10.1097/DER.0000000000000691 PubMed 33273237
- Allergic Contact Dermatitis to Fragrances. Dermatologic clinics 2020; doi:10.1016/j.det.2020.02.009 PubMed 32475515
- Limonene Hydroperoxides. Dermatitis : contact, atopic, occupational, drug 2019; doi:10.1097/DER.0000000000000465 PubMed 31433385