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Marijuana Allergy: What You Should Know

Symptoms of a marijuana allergy include coughing, sneezing, skin rash, and watery eyes.

Marijuana allergies are becoming more common today as increasing numbers of people use it for recreational and medicinal purposes. Indeed, studies show that certain individuals can experience an allergic reaction when exposed to parts of the cannabis plant.

Scientists and doctors don’t fully understand what causes marijuana allergies yet, but there are some theories.

Below is everything you need to know about marijuana allergies, and what you can do about them.

What Is A Marijuana Allergy?

Marijuana allergy
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A marijuana allergy is exactly what it sounds like. It is when you have allergic symptoms after coming into contact with the Cannabis sativa plant.

The severity of a marijuana allergy can range from having some symptoms after exposure, having hypersensitivity to marijuana, to anaphylactic shock, a life-threatening allergic reaction.

People with a marijuana allergy can have reactions to buds, flowers, roots, leaves and even seeds of the plant. They can have symptoms from smoking or touching marijuana, or even drinking marijuana tea.

The symptoms may be easy to spot, but doctors and scientists still aren’t exactly sure what causes a marijuana allergy.

“I would say that our knowledge of marijuana as an allergen is still evolving,” says Dr. Lori Connors, an allergist with Halifax Allergy and Asthma Associates.

“It’s something that’s starting to become clinically recognized, and something that we’re paying closer attention to, particularly as users of marijuana continue to increase in the general population.”

Even if we don’t know for sure what causes marijuana allergies, there are some theories about how a marijuana allergy can happen. Many theories are similar to how allergies to other plants may develop.

Environmental Exposure

In parts of the world where cannabis grows outside, some people may become allergic to the plant from exposure to airborne pollen. This is very similar to how many people experience seasonal allergies.

Regular Cannabis Use

A 2013 study on marijuana allergy found that people who smoke marijuana more often seem to show an allergic reaction to marijuana more often than people who have never smoked marijuana.


The cannabis plant contains some proteins that can be cross-reacted with some fruits and vegetables. In this case, if people are already allergic to this protein, they may have an increased risk of becoming allergic to marijuana.

Allergies to tomatoes, peaches, bananas, citrus fruits, eggplant, almonds and chestnuts have been found to cross-react with marijuana in some studies. This combination of allergies is sometimes called the cannabis-fruit-vegetable syndrome.

Dr. Connors says, “It goes along with pollen allergies, and there are some individuals who have oral allergies, which are a cross reaction between a pollen and a food that someone is ingesting. It’s called a pollen-food allergy syndrome. It seems that those individuals seem to be the ones getting marijuana allergies.”


A 2017 report looked at studies of marijuana and respiratory problems from 1970 to 2017. The researchers found that smoking in particular can cause some respiratory system symptoms, and that people with asthma should avoid smoking marijuana.

Symptoms of a Marijuana Allergy

Symptoms of a Marijuana Allergy
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There are many symptoms that can be related to a marijuana allergy. For most people, the symptoms will be very similar to those of seasonal allergies.

Common symptoms include:

  • Asthma
  • Chest tightness
  • Dry coughing
  • Sore or itchy throat
  • Skin rash
  • Blisters
  • Itchy skin
  • Headaches
  • Nasal congestion
  • Runny nose
  • Sneezing
  • Itchy nose and eyes
  • Watery eyes

Some people may feel symptoms immediately after coming into contact with marijuana, but symptoms can start up to an hour after exposure.

Symptoms often last about 30 minutes, and slowly ease after you are no longer exposed to the plant matter.

If you start to experience symptoms after coming into contact with marijuana, you should stop touching or smoking it, and make sure your symptoms don’t get worse.

If you start to notice symptoms of anaphylaxis after touching or ingesting marijuana, seek immediate medical attention.

Diagnosis and Treatment

Diagnosis and Treatment
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Marijuana allergies are diagnosed much like any other allergy, usually with a skin prick test.

In this test, the allergist pricks your skin with a needle that has a small extract of the test substance on it. If you are allergic to the substance, it will cause swelling and itching on your skin within about 30 minutes.

Blood tests can also be done to test for an allergy, but they may be more limited for marijuana until scientists understand exactly what parts of the plant are responsible for allergic reactions.

How is a Marijuana Allergy Treated?

Right now, there is no approved treatment for a marijuana allergy. If you are allergic to marijuana, the only thing you can really do is avoid it.

Pollen allergies can be treated and eventually eliminated by desensitizing you to the allergen with a course of inoculations.

Unfortunately, there is no allergy shot for marijuana yet. But given the increased numbers of reported marijuana allergies, there may be one developed in the coming years.

In the meantime, if you think you are allergic to marijuana, you should see an allergist for testing to confirm that you are actually allergic to marijuana.

If you are allergic to marijuana, your doctor may be able to prescribe you medications to help keep your symptoms under control.

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