Cannabis, also called weed, can trigger an allergic reaction just as other plants and pollens can. Depending on the type of exposure, allergy symptoms can include a cough, congestion, hives, and more.

Cannabidiol, or CBD, can also cause adverse reactions in some people.

Read on to learn more about the causes and symptoms of cannabis allergies, as well as the possible effects of CBD oil.

We avoid the word “marijuana” because it has racist roots and connotations. The word “marijuana” first became popular in the United States during the cannabis prohibition movement, as it appealed to the widespread xenophobia against Mexican immigrants at the time.

Considering that members of historically marginalized races are more likely to be arrested for cannabis possession than their white counterparts, it is especially important that we are mindful about the language we use and how it can add to, or stem from, racist stereotypes.

Medical News Today does not endorse the illegal use of any substances. However, we believe in providing accessible and accurate information to reduce the harm that can occur when using them.

In recent years, there seems to have been an increase in the number of reports of cannabis allergies. This may be because it is becoming more popular as a medicinal treatment for a range of conditions. Some states have also legalized the drug for adult use.

While cannabis may have some medical benefits, cannabis pollen can trigger allergy symptoms in some people.

According to the American Academy of Allergy, Asthma, and Immunology (AAAAI), a person can develop an allergy or allergic sensitization to cannabis after exposure to the plant. People can be exposed to cannabis allergens in the following ways:

  • inhaling pollen in the air
  • smoking cannabis
  • touching cannabis
  • eating cannabis

A recent small-scale study from 2018 reports that people are more likely to have a cannabis allergy if they have allergies to cat dander, molds, dust mites, or plants.

More research is necessary to establish this possible link.

According to a 2022 review, the most common type of cannabis allergy is an immediate hypersensitivity or immune response, with symptoms affecting the respiratory system and skin.

Common symptoms of a cannabis allergy, many of which are similar to seasonal allergy symptoms include:

Cannabis can also cause other similar symptoms that are not due to an allergy. These can include dry eyes, dry mouth, and constipation.

Handling the drug may also cause contact dermatitis, a skin reaction that can cause the following symptoms:

  • blisters
  • dry skin
  • hives
  • itchiness
  • skin inflammation

Symptoms of cannabis allergies can develop immediately after exposure to the plant. Sometimes, the symptoms may take some time to appear.

A person who notices these effects should stop touching or using cannabis immediately to prevent symptoms from worsening.

Cannabis can also cause a severe allergic reaction called anaphylaxis. This condition can be life threatening and occurs within seconds or minutes of exposure to an allergen.

Anaphylaxis: Symptoms and what to do

Anaphylaxis is a severe allergic reaction that can be life threatening. The symptoms develop suddenly and include:

  • hives
  • swelling of the face or mouth
  • wheezing
  • fast, shallow breathing
  • a fast heart rate
  • clammy skin
  • anxiety or confusion
  • dizziness
  • vomiting
  • blue or white lips
  • fainting or loss of consciousness

If someone has these symptoms:

  1. Check whether they are carrying an epinephrine pen. If they are, follow the instructions on the side of the pen to use it.
  2. Dial 911 or the number of the nearest emergency department.
  3. Lay the person down from a standing position. If they have vomited, turn them onto their side.
  4. Stay with them until the emergency services arrive.

Some people may need more than one epinephrine injection. If the symptoms do not improve in 5–15 minutes, or they come back, use a second pen if the person has one.

Along with anaphylaxis, the main risks of a cannabis allergy are its potential links to cross-reactivity with other allergens.

Cross-reactivity happens when the proteins, such as pollen, in the cannabis plant resemble the proteins in another plant. An allergic reaction may then occur when a person comes into contact with similar proteins elsewhere.

Foods with proteins that resemble cannabis proteins that may cause an allergic reaction in people with cannabis allergies, include:

Doctors diagnose cannabis allergies in the same way as other types of allergies: by using skin tests or blood tests.

Skin tests

A doctor will first take a person’s medical history and perform a physical examination. They may then use a skin prick test. This test is not very invasive and the results come back quickly.

In a skin prick test, the doctor will apply a diluted allergen, such as cannabis, to the skin’s surface with a needle. If a red bump or wheal, itching, and redness develop in that area within 15 minutes, a person may be allergic to that substance.

A doctor may also use an intradermal test. This test involves using a thin needle to inject a diluted allergen just below the skin’s surface.

Blood tests

Sometimes, a doctor or healthcare professional will do a blood test to check for a cannabis allergy. They draw a sample of blood and test it for the presence of antibodies to cannabis. If a person has more antibodies in the blood than expected, they are more likely to have an allergy to cannabis.

Blood tests may be a better option than skin prick tests for some people because they involve a single needle prick. They are also less likely to be affected by any other medications. However, the results take longer to come back, and the tests are more expensive than skin tests.

There is no treatment specifically for cannabis allergy. However, the Allergy & Asthma Network suggests that intranasal corticosteroids and nasal decongestants may help.

If a person experiences anaphylaxis, they will require an epinephrine injection.

If a person experiences an allergic reaction to cannabis, it is best to avoid smoking, eating, or touching the plant or the drug to prevent symptoms.

If a person has a severe allergy to cannabis, they should carry an epinephrine injection, such as Adrenaclick or EpiPen, in case of accidental exposure and subsequent anaphylaxis.

Avoiding exposure to cannabis is the only sure way to prevent an allergic reaction to the plant or drug.

A person who is using medical cannabis and suspects that they may be allergic to it should speak with their doctor to find an alternative treatment.

People who work in a cannabis processing plant should limit exposure by using:

  • allergy medications
  • face masks
  • gloves
  • inhalers

Is CBD legal?The 2018 Farm Bill removed hemp from the legal definition of marijuana in the Controlled Substances Act. This made some hemp-derived CBD products with less than 0.3% THC federally legal. However, CBD products containing more than 0.3% THC still fall under the legal definition of marijuana, making them federally illegal but legal under some state laws. Be sure to check state laws, especially when traveling. Also, keep in mind that the FDA has not approved nonprescription CBD products, and some products may be inaccurately labeled.

Cannabidiol (CBD) is a substance that comes from the cannabis plant. It is available in a variety of forms, including oil, gummies, lotions and creams, and vaporizers. People use CBD for a variety of purposes, including pain relief or as as a topical treatment for skin disorders.

CBD is different from tetrahydrocannabinol (THC), the psychoactive substance in cannabis. Pure CBD does not have mind-altering effects. Only THC produces these “highs.” In contrast, CBD may have antipsychotic and anti-inflammatory properties.

There is currently limited information on CBD and allergic reactions. Some people may not tolerate CBD and can experience side effects. Some people may also be allergic to certain terpenes, such as linalool and D-limonene, which CBD and cannabis may contain.

The Food and Drug Administration (FDA) notes that CBD can cause adverse effects, such as liver damage. It can also interact with medications the individual is taking.

Allergy to Epidiolex

The FDA has only approved one CBD-based drug for medical use, Epidiolex, to treat some seizure disorders. The drug’s prescribing information does not indicate any specific allergic reactions but lists the ingredients, which include sesame oil, which can cause allergic reaction in some people.

There is little evidence of people having an allergic reaction to Epidiolex, but one case report indicates that one person had an Epidiolex-induced skin rash.

Some CBD products contain THC, but manufacturers do not always indicate how much a product contains, even when there is a label. For this reason, most consumers do not know how safe their CBD oil is, especially if they use it in high quantities.

When using CBD oil or other forms, it is best to try a small amount first, to ensure it does not cause a reaction.

Cannabis allergy can cause symptoms similar to those of seasonal allergies, such as coughing, a runny nose, and itchy eyes. Skin reactions are also possible. In severe cases, a person may experience anaphylaxis, which is a medical emergency.

Avoiding cannabis is the best way to prevent an allergic reaction. When a person avoids the drug and its pollen, their symptoms may resolve.

Those who are severely allergic to cannabis should seek medical treatment. They may need to carry medication with them in case of exposure. Medications such as nasal decongestants and intranasal corticosteroids may help with mild symptoms.

Talk with a doctor before trying CBD as it may interact with other medications.