When a person’s immune system overreacts to what would normally be a harmless substance, they are having an allergic reaction. The substance may be an airborne particle like pollen, dust, or pet dander; allergens can also be found in food (peanuts, melon, soy, wheat, or milk, for example), in materials that come in contact with the skin (like a soap or detergent), or in a gaseous state, like air pollution or a diffused scent. The body’s reaction can range from sneezing and coughing to stomach cramps, ringing in the ears, and hives. Some severe allergies can cause anaphylaxis, a fast-moving process that swells the throat and tongue, making it difficult or impossible to breathe.
People and pets can be allergic to essential oils. The symptoms will vary from one person to the next, and chances are that the allergy will be to one specific oil or a family of oils, not to the entire compendium of essential oils. Just as people may be allergic to ragweed but have no adverse reaction to goldenrod, a person may be allergic to lavender essential oil, for example, but not peppermint or sandalwood.
An allergic reaction to essential oils can take one or more of many forms. Some people who mix essential oils into their hand or body lotion may develop contact dermatitis, a red rash that surfaces when the essential oil comes into contact with the skin. The rash may become worse, resulting in cracked skin, oozing sores or blisters, and pain or a burning sensation. Contact dermatitis may be a sign of general irritation rather than an allergy, perhaps from using too much essential oil without blending it into a carrier oil or lotion. Stop using the oil until you have determined if you have an allergy or simply failed to mix the essential oil and carrier oil thoroughly.
Reviews of skin patch tests in 2010 and 2012 revealed that certain essential oils are more likely to cause an allergic reaction than others. It is interesting to note that some of these are among the most popular essential oils in use worldwide, which may be the reason we know more about their potential for allergic reaction than others:
- Clove
- Jasmine
- Lavender
- Lemongrass
- Peppermint
- Sandalwood
- Tea tree
- Ylang-ylang
This list is not exhaustive; other essential oils may cause allergic reactions, but they may not have been studied for their potential as allergens.
Beyond a red rash, some people develop hives, also known as urticaria, from using essential oils. It can be very difficult to pinpoint the cause of hives, as a wide range of factors can make them appear, from food allergies to stress. You can tell them from contact dermatitis fairly easily, however, as hives are raised welts on the skin, often several inches long and very itchy. They may come and go over time, making it particularly tricky to determine if they appeared as a reaction to an essential oil—and they can be caused by things like foods that have no direct contact with skin.
To help predict if an essential oil will cause an allergic reaction, perform a simple skin test. Place a drop or two of the essential oil in a teaspoon of carrier oil, and rub this on the skin on the inside of your elbow. Cover this and wait for 24 hours, and then remove the covering (gauze or a Band-Aid will do) and see if you have a rash, swelling, or hives. If you don’t see any irritation, chances are the essential oil is safe for you to use. If you do have a reaction, you can wash the area with mild soap and water to remove the last of the essential oil; if the reaction is severe, try running cold water over a washcloth and applying this to the affected area to soothe the burning and itching.
Essential oils used in a diffuser can generate an allergic reaction—most likely sneezing, coughing, nasal or chest congestion, and runny nose. This can be particularly pronounced in people with severe hay fever and seasonal allergies, chronic sinusitis, asthma, or chronic obstructive pulmonary disease (COPD). If you suffer from any of these health issues, it may be wise to forgo an essential oil diffusion in your home or workplace. Try a short-duration diffusion (perhaps five minutes) in a room to see if it affects your ability to breathe or if it triggers an allergic response. If your body reacts negatively to the essential oil diffusion, stop using it.
Some essential oils can cause eye irritation, but this is more a factor of people forgetting to wash their hands after adding an essential oil to a diffuser. If you have essential oil on your hands and you touch your eye, your eye may become irritated, producing a burning sensation. Flush your eye with water if this happens; if the irritation does not clear up in a few minutes, call your ophthalmologist.
