- Fact-checked by Dr. Desiree Granados
Both medical and recreational marijuana come from the cannabis sativa plant. Humans have consumed marijuana for thousands of years to manage symptoms of various conditions and experience psychoactive “highs.” The rising profile of weed in recent years is thanks to a growing body of research exploring its medicinal effects and researchers’ recent insights into its relatively low risk of abuse.
But just as humans can be allergic to flowers or grass, they can also be allergic to weed. It is vital to recognize the difference between typical side effects of marijuana and an allergic reaction to it. Depending on the strain, dose, and your individual biochemistry, marijuana can cause a variety of side effects. Allergic reactions will be consistent and typically worsen over time.
Learning the signs and causes of a cannabis allergy is critical due to the growing accessibility and therapeutic potential of marijuana. This article explains the symptoms of cannabis allergies, why they happen, and ways to treat allergic reactions.
Symptoms of Marijuana Allergies
Just like other plants, cannabis contains allergens and proteins that cause reactions in people with sensitivities. The symptoms can range from mild to severe. The response usually worsens with repeated exposure (a process called sensitization). Beyond consuming cannabis, exposure to pollen can cause reactions. Individuals who work on cannabis farms or at processing facilities take precautions to limit pollen exposure.
Common signs and symptoms of a cannabis allergy from smoking or ingesting weed include:
- Congestion
- Diarrhea
- Hay fever
- Nausea
- Red and watery eyes
- Runny nose
- Sneezing
- Vomiting
You can also have a skin reaction called contact dermatitis from simply touching marijuana. The irritation often presents as hives, itchiness, red skin, or scaly and dry skin.
The most severe symptom is anaphylaxis, a bodywide reaction where blood pressure drops and the airway closes, depriving a person of oxygen. This reaction is potentially fatal. It requires immediate medical attention.
Causes of Marijuana Allergies
Allergic reactions result from a protein in marijuana that the body perceives as a threat. As a result, the immune system triggers and attacks the foreign body. This biological response leads to allergy symptoms.
The protein is present in vapor from marijuana smoke, the parts of the plant or concentrate contained in edibles, and on the plant itself. Inhalation, ingestion, or skin contact allows the protein to enter the body, activating a response.
The ongoing federal prohibition limits the scientific understanding of marijuana allergies. Despite evolving notions on the safety and medicinal value of cannabis, research still faces challenges due to federal law. As a result, there is no approved skin-testing method for cannabis allergy, as there is with conditions like ragweed or nut allergies.
Scientists speculate the spread of marijuana cultivation to meet patient and consumer demand is contributing to the growing prevalence of weed allergies. When the plants release pollen, it can travel for miles and enter the human body, beginning the sensitization process.
Risks of Marijuana Allergies
The main risk of marijuana allergies is that they progress and worsen with each subsequent exposure. In many cases, your initial response may be mild and brief. With consistent marijuana use, your body becomes more sensitive, leading to longer-lasting and more pronounced symptoms.
Due to the legal status of marijuana, researchers have limited data on the extent and severity of weed allergies. Anecdotal evidence suggests anaphylactic reactions are relatively rare. However, cases may be underreported or misreported due to the legal gray area surrounding marijuana.
You are at higher risk of developing a weed allergy if you are allergic to substances with similar protein profiles. Be especially vigilant if you are allergic to:
- Almonds
- Apples
- Bananas
- Chestnuts
- Eggplant
- Grapefruit
- Peaches
- Tomatoes
Using marijuana with high THC levels increases the allergy risk. Modern cannabis cultivation yields plants with potent THC content by isolating and only growing female plants. A byproduct of this process is higher levels of terpenes and essential oils. These increased concentrations can make people more sensitive to cannabis.
Marijuana Allergy Treatment
There is no way to cure an allergy. The best treatment is to minimize cannabis exposure. As a result, abstaining from cannabis and avoiding its pollen is the only way to prevent allergic reactions.
If you experience a reaction, remaining calm is the critical first step. Almost all cases are non-life-threatening. Over-the-counter allergy medications and antihistamines can usually manage mild symptoms like runny nose, sneezing, and itchiness. If you suspect you have a cannabis allergy, consulting your doctor or an allergist can help determine if the marijuana plant itself is the culprit. Allergy testing can rule out other allergens.
If you undergo allergy testing, it will likely be a blood test. More specifically, it will likely be a skin prick test. Your allergist will conduct the test to determine whether you have certain antibodies in your blood. Those who are allergic to cannabis make antibodies in response to marijuana products, which can result in unpleasant side effects like difficulty breathing. Products containing both cannabidiol (CBD) and tetrahydrocannabinol (THC) can induce such reactions and compromise your health and wellness.
In the case of anaphylaxis, the only treatment is a shot of epinephrine and immediate medical attention. Severe allergic reactions can be fatal because the swelling that closes the windpipe cuts off the oxygen supply. As a result, you must act fast because minutes are critical.
FAQ
How would you know if you were allergic to weed?
Generally, the symptoms of an allergy to weed mimic allergic reactions to plants and consumables. You can develop itchy, red, and watery eyes. Many people experience hay fever symptoms like sneezing, runny nose, and wheezing. If you ingest edible cannabis, you may experience gastric distress, nausea, vomiting, and diarrhea.
Skin exposure to the plant can cause a rash, reddened skin, itching, hives, and dry or patchy skin that resembles eczema. If you believe you are reacting to cannabis, remain calm. The psychoactive effects of weed can sometimes cause anxiety and fear, leading you to misinterpret typical side effects as allergic reactions.
Is it rare to be allergic to weed?
Unfortunately, the lack of high-quality reporting on allergic reactions to weed makes it challenging to know with certainty. Some researchers estimate up to 10% of marijuana users are allergic to weed.
The evolving societal views on medical and recreational marijuana mean more cases are likely to be documented as legal use expands. This evolution will allow investigators to develop their understanding of the nature of weed allergies, precautions, and treatments.
Fortunately, reports of anaphylaxis from weed are rare.
What does a weed allergy do?
A weed allergy causes an adverse biological reaction to a protein present in the cannabis plant and consumable weed. It generally provokes mild symptoms that resolve once the allergen leaves the body or you are no longer in contact with the plant or its pollen.
Why am I allergic to weed now?
Repeated exposure to an allergen can lead to sensitization or increasingly pronounced symptoms. If you are a medical marijuana patient or habitual recreational user, exposure to the cannabis allergen can increase your sensitivity to it and intensify your reaction.
How we reviewed this article:
- What Is A Marijuana Allergy?
https://www.nyallergy.com/marijuana-allergy/ - Risk factors of a cannabis allergy
https://www.healthline.com/health/allergic-to-marijuana#symptoms - Marijuana Cannabis Allergy
https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/marijuana-cannabis-allergy
Current Version
February 20, 2023
Written By
Jake Peter
Fact-checked By
Dr. Desiree Granados
Editorial Process
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Jake Peter received his journalism degree from Emerson College and has been writing content for the Sanctuary Wellness Institute since 2021. He is passionate about all things cannabis.
