Patch Testing and What to Do After a Skin Reaction
What sources say about skin reactions to essential oils, when a patch test is suggested, why reactions can appear days later, and when to get urgent help.
Content last updated . This page has not been medically reviewed.
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Urgent first
Call 911 if, after contact with an essential oil, the lips, mouth, throat or tongue suddenly swell, breathing is difficult, or the person becomes very confused, drowsy or dizzy. The NHS (UK) lists these among signs of a serious allergic reaction needing urgent treatment. [1] Poison Control says any allergic reaction that includes difficulty breathing should be treated as a medical emergency. [2]If an oil has been swallowed, call Poison Help at 1-800-222-1222 (US). [2]
The short answer
A patch test is a small trial of a product on a limited area of skin before wider use. The National Association for Holistic Aromatherapy (NAHA, a US professional association) says that if a person has known allergies or sensitivities, a skin patch test may be wise. [3] Sources do not describe a patch test as a guarantee. The NHS says a reaction usually occurs within a few hours or days of exposure to an irritant or allergen, so skin that looks fine at first can still react later. [4]This page does not give a step-by-step test, amounts or timings. A pharmacist or a dermatologist can advise what suits a person. A "patch test" done in a clinic by a dermatologist is a different, medical test.
Three kinds of skin reaction
| Type | What sources say |
|---|---|
| Irritation | NAHA says an irritant produces an immediate effect, blotchy or red skin that may be painful, and that its severity depends on the concentration applied. [3] |
| Allergy (sensitization) | Poison Control says the most common type of allergic reaction to essential oils is a skin rash. [2] NAHA says that once sensitization occurs, a person is most likely to stay sensitive to that oil for many years. [3] The NHS says allergic contact dermatitis can be triggered by substances in certain products, such as cosmetics. [4] |
| Sun reaction | The National Cancer Institute (NCI, US) says sun sensitivity may occur when citrus or other oils are applied before going out in the sun. [5] See phototoxicity and citrus oils. |
An educator, Robert Tisserand, writes that of the irritant, allergic and sun-related reactions, allergic reactions are the most common. [6] This is one author's view.
Why age and air matter
A Danish study of 6,719 patch-tested patients reports that limonene and linalool, common fragrance chemicals, autoxidise on air exposure into potent sensitisers; most patch-test reactions to them peaked on day 3 or 4. [7] This is a clinic study of two fragrance chemicals, not a test of home products. See skin reactions and sensitization.What sources say to do after a reaction
- Stop and wash. Poison Control says to stop using the product immediately if a rash or other skin reaction occurs, and to gently wash it off. [2] It adds that if a rash occurs, the remaining oil should be washed off with soap and water. [2]
- Rinse. For contact dermatitis in general, the NHS suggests rinsing the affected skin with warm water and an emollient as soon as possible. [4]
- Vegetable oil or cream. NAHA says to apply a small amount of vegetable oil or cream to an irritated area and to stop using the oil or product that caused it. [3]
- Do not use it again. NAHA advises avoiding the same oils every day for lengthy periods, because that can lead to sensitization. [3]
- Tell a clinician. The NHS says to see a doctor for persistent, recurrent or severe symptoms. [4]
- Eyes and mouth. Keep oils away from the eyes. [3] See eyes, ears and mucous membranes.
Frequently asked questions
Does a patch test prove an oil is safe?
No source we read says so. The NHS says reactions can appear hours or days after exposure. [4]
What should I do if I get a rash from an essential oil?
Poison Control says to stop using it and gently wash it off with soap and water. [2] See a doctor if it persists or is severe. [4]
Can I become allergic after using an oil for a long time?
NAHA says sensitization can follow repeated use and may last for many years, so avoid daily long-term use of the same oil. [3]
Is a delayed reaction possible?
Yes. The NHS says contact reactions usually occur within a few hours or days. [4]
When is it an emergency?
Trouble breathing or swelling of the throat, tongue or lips. Call 911. [2] [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Limits of what we know
- The sources we read do not say how well a home patch test predicts a later reaction. Proper evidence not found. We searched for dermatology guidance on home patch testing of essential oils and could not read an American Academy of Dermatology page.
- The reaction can come from another ingredient. Poison Control says people can be allergic to other ingredients in an essential oil product, labeled or unlabeled. [2]
- Peppermint and lavender products carry their own notes: NCCIH lists skin rashes and irritation for peppermint oil, and allergic skin reactions for lavender products. [8] [9]
Tell the prescriber, pharmacist or surgical team about regular use of oils, especially before a procedure. See essential oil safety.