Essential oils are currently the “cool kids” of the wellness scene, touted for health benefits ranging from relieving anxiety, fighting infections, easing headaches, and more.

But if used improperly, essential oils can cause allergic reactions, among other adverse effects.

Read on to learn how to spot symptoms of an allergic reaction to essential oils and tips for safely using this alternative treatment.

Essential oils are aromatic compounds extracted from plants. They play a central role in aromatherapy, which is a type of holistic health treatment that promotes health and well-being.

Much of the hype surrounding essential oils stems from the fact that they are natural products.

This doesn’t necessarily mean that essential oils are totally safe. These complex substances aren’t regulated by the Food and Drug Administration, and some of their health benefits are overstated.

There are dangers associated with using aromatherapy around pregnant women, children, and pets. There are dangers associated with incorrect use. It is possible to be allergic to essential oils.

Allergic reactions are quite common. They occur when your immune system overreacts to an allergen — a substance that is normally harmless.

The allergen triggers your body to start producing antibodies, which produce chemicals to “attack” the allergen.

Allergic reactions range from mild to life-threatening, and they result in symptoms that usually affect your nose, lungs, throat, skin, stomach, sinuses, or ears.

In aromatherapy, essential oils are usually diffused into the air and inhaled, or diluted with a carrier oil and applied to the skin. Essential oils shouldn’t be ingested.

Symptoms of an allergic reaction to essential oils can vary based on the person and how they use the oils. Here are the most common types of allergic reactions and the symptoms of each:

Contact dermatitis

Contact dermatitis is an itchy, red rash that develops when certain substances touch your skin directly.

There are two types: irritant contact dermatitis and allergic contact dermatitis.

In addition to itchy, red rash, both types of contact dermatitis share other symptoms:

  • dry, cracked, or scaly skin
  • oozing blisters or bumps
  • burning and stinging sensation

Allergic contact dermatitis is the most common allergic reaction to essential oils. It occurs when you become sensitized to an allergen and have a reaction after a subsequent exposure.

It’s a delayed hypersensitivity reaction, which means that you might not notice symptoms until 12 to 72 hours after exposure.

Irritant contact dermatitis isn’t a true allergic reaction. It occurs when your skin is exposed to a toxic or irritating substance. Its rash is usually more painful than itchy and gets worse the longer you’re exposed to the substance.

If you have dermatitis related to an essential oil, the oil may not have been diluted enough in a carrier oil. Discontinue use of the essential oil and allow the area to heal before trying a different essential oil.

Hives

Hives (urticaria) have many possible triggers, including food, medication, insect stings, infections, and more. They can appear on any part of your body and are characterized by:

  • raised red bumps (welts) that often itch
  • welts that can vary in size and often repeatedly appear and fade

Phototoxic reactions

Some essential oils are photosensitive or phototoxic, which means that they can cause a serious reaction if you apply them topically and then expose your skin to the sun’s UV rays.

Citrus essential oils, including lemon, lime, orange, and bergamot, are known to cause photosensitive reactions.

The symptoms of such reactions are:

  • skin redness or discoloration
  • burning or itching
  • blistering

If you choose to use a photosensitive essential oil, avoid exposing your skin to UV rays for at least 12 hours.

Nasal irritation

If you’re diffusing essential oils, you may experience nasal symptoms such as:

If you have asthma, consult your doctor before diffusing essential oils.

Eye irritation

Putting essential oils in your eyes or accidentally touching your eyes after handling essential oils can result in:

  • eye redness
  • irritation
  • burning

If you suspect that you’re having an allergic reaction to an essential oil, stop using it immediately. Open your windows and clear the air.

Most reactions to essential oils are mild and can be treated at home.

If you applied the oil topically, thoroughly wash the affected skin with gentle soap and cool water.

Applying a cold, wet compress to your skin can feel soothing. You can also apply a mild hydrocortisone cream to the rash to relieve itching.

If you get essential oil in your eyes, flush your eyes with cool water and seek medical advice.

Call your doctor if your symptoms persist or get worse. A couple of situations require immediate medical attention, however:

Ingesting oils

Ingesting essential oils is dangerous. If you accidentally swallowed an oil, immediately call the Poison Control hotline at 800-222-1222 and follow these precautions:

  • Don’t try to induce vomiting.
  • Keep the essential oil bottle on hand to help the emergency response team assess the situation.

Anaphylaxis

Anaphylaxis is a severe, life-threatening allergic reaction that requires emergency medical attention. Experiencing an anaphylactic reaction to essential oils is rare, but possible.

Call 911 or local emergency services immediately if you notice any of the following symptoms:

  • swollen throat or other swollen body parts
  • wheezing and trouble breathing
  • vomiting or stomach cramping
  • difficulty swallowing
  • feeling of impending doom

Discontinue the aromatherapy and get into fresh air immediately. If using an essential oil in an oil topically, wipe off the oil with a dry towel and then wash the skin.

Although nearly 100 varieties of essential oil are commonly used, there isn’t a large body of comprehensive research on their potential for causing allergic reactions.

However, a 2010 review of patch test results and a 2012 review of case studies identified the following essential oils as being more likely to cause skin irritation:

  • tea tree
  • ylang-ylang
  • sandalwood
  • lemongrass
  • jasmine absolute
  • clove
  • lavender
  • peppermint

Also consider whether your carrier oil could cause skin irritation. Common carrier oils include coconut, jojoba, and grapeseed. It is possible to be allergic to these.

When using essential oils, it’s important to take precautions to avoid adverse reactions:

Dilute, dilute, dilute

Essential oils need to be diluted with a carrier oil to prevent irritation. Follow these dilution guidelines and choose a high-quality carrier oil.

If you’re allergic to nuts, you shouldn’t choose carrier oils derived from tree nuts, such as almond or argan oil.

Do a patch test

A patch test allows you to see how your skin reacts to a substance before using it more widely. Here are the steps for performing a patch test:

  1. Wash your forearm with mild, unscented soap, and pat the area dry.
  2. Dab a few drops of diluted essential oil onto a patch of skin on your forearm.
  3. Place a bandage over the patch, and keep the area dry for 24 hours.

If you notice any rash, irritation, or discomfort during the 24 hours, remove the bandage and wash your skin thoroughly with gentle soap and water. Don’t use the essential oil if any reaction develops during the patch test.

If no irritation develops during the 24 hours, it’s likely safe for you to use the diluted essential oil. However, a successful patch test doesn’t mean that you won’t develop an allergy or experience a reaction after future use.

Use fresh oils

The composition of essential oils can change over time due to age and storage conditions. They may oxidize, which increases the potential that they could cause an allergic reaction or other problem.

All essential oils degrade over time, but storing them in a cool place away from direct light can help slow down the process. Make sure you cap them tightly to prevent oxidation.

If you notice that an oil has changed color, smell, or texture, it’s best to throw it away and buy a fresh bottle.

Using essential oils around children and during pregnancy is highly controversial and should only be done under the guidance of a healthcare professional.

Children have thinner, more sensitive skin that makes them more vulnerable to adverse reactions. They may also react after inhaling aromatherapy not even meant for them. So it’s important to keep essential oils stored safely out of reach of babies and children.

There are concerns that using essential oils during pregnancy could harm your fetus if the oils cross over into the placenta. We just don’t know for sure what is safe, so check with your healthcare provider and talk with a certified aromatherapist if you’re pregnant or breastfeeding.

Essential oils are natural products, but this doesn’t mean that they are free from health risks. It’s possible to experience an allergic reaction from using them, for example.

Essential oils can serve as a beneficial part of your wellness or beauty routines, as long as you know how to use them properly.

Talk to your healthcare provider about whether it’s safe for you to use essential oils and the best practices for doing so.