Cannabis Allergy 101: Can You Be Allergic to Cannabis?

Unfortunately for many who work in the cannabis industry, the risk of cannabis allergy is very real. This reaction is characterised by a red, prickly rash over exposed skin, often accompanied by mild to moderate respiratory irritation (often including coughing and sneezing). It’s most often found among those who work in close contact with the growing cannabis plant.

Although the incidence of cannabis allergies among consumers is generally low, those who work in close contact with the growing plant often report allergy symptoms. Cannabis pollen as well as certain proteins found to be present in the growing plant have been identified as the main culprits for cannabis allergens. Contact with these allergens can cause dermatitis-like symptoms such as redness and rash, as well as sneezing, coughing and shortness of breath.

Those prone to allergies from contact with the cannabis plant are often prone to allergies from contact with many other plants. A cannabis allergy should not be confused with Cannabis Hyperemesis Syndrome, which is associated specifically with cannabis consumption. Cannabis allergies occur by contact and exposure to cannabis pollen (working on a cannabis farm, trimming, etc.).

What are the symptoms of cannabis allergy?

Cannabis allergy symptoms are most often reported to be similar in presentation to contact dermatitis, and are most commonly reported by individuals who work on cannabis farms, trimmers and sometimes even those who work in dispensaries. Such individuals typically report itchiness and redness on skin, which can develop into a rash or hives in severe cases. The eyes may also become red, itchy and inflamed.

As well as dermatitis-like symptoms, cannabis allergy can also cause respiratory symptoms including allergic rhinitis, asthma. Other symptoms include allergic conjunctivitis, food allergy, eczema, drug eruption, contact urticaria and anaphylaxis.

In severe cases of cannabis allergy, anaphylactic shock can occur. Anaphylactic shock is characterized by the rapid onset of symptoms such as itchy rash, shortness of breath, lightheadedness, throat or tongue swelling, vomiting, and low blood pressure. If untreated, anaphylactic shock can cause loss of consciousness and even death (although there do not appear to be any known deaths as a result of cannabis-induced anaphylaxis).

What causes cannabis allergy?

First off, it is important to differentiate between true cannabis allergy and allergic reactions to substances found in cannabis that are not endogenous to the plant, such as moulds or dust mites. It is well known that poorly grown and poorly stored cannabis can contain both, and both are well known to cause strong allergic reactions in many individuals.

There have been several cases of severe reactions occurring in individuals who smoke mouldy weed, and at least one death has been attributed to it (although importantly, the individual in question was severely immune-compromised due to recent surgery).

However, cannabis allergy itself is a specific allergy to a substance or substances contained within the plant. In fact, there are several substances that may represent a risk to sensitive individuals, and it may be that different cases of cannabis allergy occur in response to different substances.

Histamine is an organic nitrogenous compound, and is synthesised in the body by the decarboxilation of the amino acid histidine. Histamine has a vital role in regulating local immune response. When allergens are present at certain key areas of the body (such as the mucous membranes), histamine is released by mast cells or white blood cells known as basophils in a process known as degranulation.

Degranulation is a mechanism whereby certain cells involved in immune response release cytotoxic compounds that destroy invading microorganisms such as allergens. When such allergens enter the body, the molecules of the free-floating antibody protein known as immunoglobulin E (IgE) bind to Fc receptors found on the surface of the mast cells and basophils.

The allergens then bind to the IgE, and the cell begins to release histamine. This triggers the inflammatory response and increases the permeability of the capillaries to allow certain white blood cells and proteins to directly attack the invading pathogens.

This is the physiology behind how the body deals with allergens. The immune response is important for maintaining health, especially against foreign bodies. However, allergies are often considered to be an overreaction of the immune system, producing histamine in the absence of an actually threatening foreign substance. Different substances in cannabis (and in other plants) trigger this sensitivity in certain individuals, resulting in symptoms otherwise referred to as hay fever. 

Different cannabis allergens

The most likely allergen to cause a reaction is cannabis pollen. This is typically only produced by male plants, but can also be produced by females that express hermaphroditic male flowers (and in severe cases of hermaphroditism, there can be a significant amount floating in the air).

Cannabis and hemp pollen has been shown to cause allergic reactions in several studies, and individuals who show sensitivity to it typically also are sensitive to pollen from other plants. A study conducted in 2000 in the U.S. Midwest showed that 73% of the subjects were sensitive to cannabis pollen, and that each of those individuals was also sensitive to local plants such as ragweed, Russian thistle and cocklebur.

However, this does not explain the cases of cannabis allergy that are caused by female plants with no signs of hermaphroditism. In these instances, something else is clearly to blame, and scientists have pinpointed almost a dozen possible culprits.

Most of the possible allergens found in cannabis are proteins, and many of them have been found in other plants and have been confirmed to be allergens. Several studies have pointed to the existence in cannabis of a particular type of protein known as a lipid transfer protein (LTP), which are often implicated in allergies.

Cannabis LTP, the possible key to the allergy

Several studies into cannabis allergy have pointed to the existence of an LTP or LTPs present in the growing plant. One study published in 2007 actually reported that a unique LTP had been isolated in cannabis, which was subsequently named Can S3. In at least one study, patients have shown specific sensitivity to the substance described as Can S3 when undergoing skin prick tests and other immunological test. However, as Can S3 sensitization is not absolute, other cannabis allergens probably play a role.

In a pertinent study published in the Annals of Allergy, Asthma & Immunology in 2013, the researchers did not find any evidence of an LTP protein present in cannabis. However, they found strong evidence of other common allergens.

Other potential cannabis allergens

In the same 2013 study mentioned above (published in the Annals of Allergy, Asthma & Immunology), several other potential allergens for cannabis are isolated and identified. Common allergens found in nature were confirmed to be present in cannabis including RuBisCO, a protein that is fundamental to the photosynthesis process. It has been implicated in many other cases of plant allergies.

As well as RuBisCO, researchers identified a protein in cannabis known as oxygen-evolving enhancer protein 2. It was a prominent allergen in this research, although interestingly, it has never been identified or investigated as an allergen in any other allergen study, cannabis or otherwise.

Along with these two proteins, several other potential candidates were found: ATP synthase, GAPDH (a major known allergen in wheat and fungi), PGK (yeast allergy), BiP (hazelnut allergy).

Cross-sensitivity with other plants

Individuals who are found to be allergic to cannabis are also found to be allergic to tobacco and tomato. This association has been noted on several occasions, and it has also been noted in a study published in 2011 that latex also has cross-reactivity with this group of plants.

In a 2008 study conducted in Spain, it was found that cannabis sativa Leaves sensitive individuals were highly likely to be sensitive to tomato and peach.

Interestingly, being sensitive to pollen does not necessarily mean that an individual will be allergic to cannabis, and vice versa. In the 2011 study, it was found that pollen allergy was not associated with cannabis allergy itself. This implies that individuals can be allergic to only the pollen, or only the other allergens present, but that it is unlikely for someone to be allergic to both.

How to reduce symptoms of cannabis allergy

For the most part, allergic reactions can be treated with antihistamines (a group of medications that stop the production of histamines by immune cells). Hay fever symptoms as well as allergies to fruits and other plants can be reduced with an antihistamine. However, this is not true for anaphylaxis that usually requires adrenaline administration.

Therefore, there is no true cannabis-specific medication for dealing with allergy. Those who experience cross-sensitivity can simply use the same medications they would use to treat other plant allergies.

Otherwise, there are various ways in which one can minimise exposure to cannabis allergens, especially during times when risk of exposure is high. High exposure risk is generally limited to workers in close physical proximity to the plants. However, as demonstrated in the US Southwest, pollen can travel for miles, and can therefore cause high-risk periods in certain areas at certain times of the year.

Wearing long-sleeved clothing is advisable, as well as masks, gloves, goggles, and other physical barriers to contact. Use inhalers, antihistamines, and epi-pens only if allergy symptoms occur. Ensure that airflow is optimum, so that allergens do not hang around in the air too much.

Finally, the best method for ensuring that allergic reactions do not occur is to avoid exposing oneself to the source as much as possible. Many individuals that work with cannabis continue to expose themselves year after year in the hope that their sensitivity will decrease, but this is highly unlikely to be the case. If seriously affected, avoiding all physical contact and proximity to the plant is recommended, which may mean that continuing to work with cannabis is impossible for some.

  • Disclaimer:
    This article is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with your doctor or other licensed medical professional. Do not delay seeking medical advice or disregard medical advice due to something you have read on this website.

Comments

20 thoughts on “Cannabis Allergy 101: Can You Be Allergic to Cannabis?”

  1. Clarisa Robishaw

    Symptoms of allergic rhinitis resemble a cold, but they are not caused by a virus the way a cold is. When you breathe in an allergen, your immune system springs into action. It releases substances known as IgEs into your nasal passages, along with inflammatory chemicals such as histamines. Your nose, sinuses, or eyes may become itchy and congested. Scientists aren’t sure what causes your immune system to overreact to an allergen.”

  2. melva smith

    So glad to see this article. I tried to eat some of those packaged hemp hearts for health reasons and i swole and got a prickley hivey sensation all over. I felt strange too and my throat became puffy and irritated. If exposed while walking past hemp smoke, i break out in hives. So glad that some of the hud housing properties are banning smoking i general in apartment units. People have to go outside. I cant imagine the living misery this stuff would put a person through if an inconsiderate neighbor refused to take it outside. Praises to HUD.

  3. I got an Oral Allergy Syndrome (OAS), which is an aggravation of Allergic Rhinitis, not from cannabis use but from several years of taking Prozac (fluoxetine) and other prescribed drugs. I tried different brands of fluoxetine and I always got the OAS on the sixth day. At the same time, due to fluoxetine and the other prescribed drugs, I got allergic to most Non-steroidal anti-inflammatory drugs, complex B and penicillin.

    As you know, to avoid the OAS, all raw vegetables and fruits have to be cooked in order to modify the lipid transfer protein (LTP) which is confused by our body with a protein from pollen so in order to avoid an allergy from cannabis pollen, you have to decarboxylate your cannabis (turning ATHC into THC), in other words you have to cook it (cookies, brownies, butter, etc) and eat instead of smoking it or vaporize it. This is the only way I was able to stop getting allergies and Asthma from cannabis. At least, that is my experience.

    But be careful when you eat cooked cannabis because you can get temporal or permanent psychosis since THC taken by mouth undergoes “first pass metabolism” in the small intestine and liver to 11-hydroxy which is four times more psychoactive* than unmetabolized THC, and four times more immunosuppressive

    Great article btw 🙂

    *Source: Cannabis and Cannabis Extracts: Greater Than the Sum of Their Parts?
    http://www.cannabis-med.org/data/pdf/2001-03-04-7.pdf

  4. Very insightful. I have a relative experiencing some of these symptoms, who had initially thought it was a food allergy. She recently picked up cannabis after years of not smoking. I have a feeling this is it.

  5. Rainy Woods

    I have a severe allergic reaction to flowering mj plants. When I harvested last year I was covered in tiny itchy red fire bumps on face, ears, neck, forearms and hands. I thought it was spider mite bites, but again this year when I harvested the same thing happened and plants were mite free. Sadly I am allergic to fresh flowering mj. The dried doesn’t affect me at all. I am so miserable I want to rip my face off, it isn’t worth ever growing mj again.

  6. I am sure we could get people to try out their allergies or contact dermatitis with the different strains and we would find a strain or many(i hope for this) where there are no reactions.
    I know i would like to buy seeds for this strain if there are chances that i would not react to it as i suffer from contact dermatitis. If you have found strains where the reaction is minimal please let us know.

    Thanks

    1. CancerMan777

      White Widow lineage I can’t even touch it get hives. Anything like that gets me

    2. I agree it happened to me with a particular strain. I have handled many strains but today new strains, and I got an awful blistering rash on one arm, my right one which I am right handed. It was dry but I really think its a particular strain that did this and I can only narrow it down to lemonade, berry wreck or skunk #1 because those are the strains I worked with today. I handled air dried and freeze dried. It is as bad as poison ivy but not spreading. Id like to go get a shot if I wasnt a cheap ass! It is nearly that bad

  7. Ellen Smith

    I never heard of such cases of allergy especially due to cannabis. This is new information for me. However, allergic reactions to cannabis may not be entirely due to histamine, although it is likely to be involved.

  8. At the end of august this year, my flowers were changing from babies to actual sticky, beautiful flowers. I do have fall allergies so I chalked up my symptoms to be that. However any over the counter antihistamines have not worked. So I thought, maybe a head cold. I harvested one of my girls last night and upon waking up, my symptoms have doubled at the least! Itchy, watery eyes, very red, runny nose, severe sinus pressure,sneezing fits….no cough or sore throat though. Am definitely considering the fact that I may be allergic to flowering marijuana. It doesn’t bother me until it’s in full flower, I do wear gloves and a long sleeve shirt, so no itchies. I think I will try a medical mask in addition to my harvesting wardrobe!

  9. scottyBgood

    Great article. Thanks for the info. I too suffer from this allergy and when it’s time to harvest I glove up and cover up as much as possible. Once it’s all jarred up I’m fine and since I started vaping instead of smoking thats helps.

  10. Unfortunately, After growing for over a year I have developed an allergy to my plants. My hands get red rashes and raised filled blisters. Talk about unsightly, painful and inconvenient. So, whats a girl to do?
    Cover up head to toe. Double the gloves. 5mil nitrile is not enough. Somehow the trichomes/hairs penetrate them. Vapor Respirator when flowering. Only my hands suffer so I try to be extra careful.

    What did you think I was gonna do? Stop growing? No Chance..lol
    Theres ways around everything. .Just gotta find it. HAPPY GROWING

  11. What a out mj salve? Friends gave us a jar to try out. I have fibromyalgia so I tried it on the places hurting the most… Hands, elbow, tail bone/butt crack area. Few days later I have a red bumpy itchy rash in the tail bone/butt crack area. I’m freaking out, I haven’t got my legal card yet so I can’t go to the doctor. But now my scalp and thighs are itchy too, along with my eyes! And I never get allergies. But 3 years ago I had a rash that lasted for a year. They finally figured out the name of it but not what caused it. So… Does anyone think my butt crack rash could be caused by the mj salve? No rash on hands or elbow. Please I’m desperate. Thank you.

  12. Toured large cannabis Farm yesterday. Each time we passed outside greenhouse containing plants with buds my tongue, lips, and face began to tingle. I am allergic to soy, in particular soy ink…my reaction to cannabis was akin to that of soy. We were given bottle of commercially made medicinal cannabis pain cream 30 mg THC. Within 4 minutes of applying to upper arms for pain, I was scrubbing it off, dizzy, and felt as if I was having a reaction to soy but 10-fold in severity. My ears throbbed, had cotton mouth, face felt as if I had severe sunburn, joints really hurt. Whole event lasted 2+ hours.

  13. Pauline Emery

    I started taking cannabis tincture a few weeks ago, starting with two drops in a spoon of water by mouth. I certainly felt something happening the first night and I felt a tingling on my face and throat and awoke with a very dry mouth. At first I thought this meant that good things were happening but now I think it might be an allergic reaction. I graduated to four drops at night and now I’ve developed a really bad case of an excema like rash on my face, which itches and burns horribly. I thought it was due to gluten in my diet (I know I’m sensistive to this) but it’s actually become worse. After reading the above comments, I’m going to stop the tincture for a while and see what happens.. Rather disappointed as I was really hoping to reduce inflammation in my body and I know cannabis can do that.

  14. This is very much my experience! I smoke for my pain for brittle bones disease (Bruck Syndrome) andhave developed severe rhinitis and now raised itchy white bumps with contact.
    Cannabis helps me greatly for my pain — I do have respiratory discomfort daily as a result of rhinitis. I try to vape most often (no access to edible,) but I do love my joints! I’m worried though, should I be concerned about anaphylactic shock? I don’t have any other allergies to fruits and this is the only severe allergy i have other than the occasional seasonal allergies. Please advise?

    1. Scarlet Palmer - Sensi Seeds

      Hi there,

      Thank you for your comment. We are sorry to hear about your situation. As Sensi Seeds is not a medical agency or practitioner, we cannot give any kind of medical advice other than to consult our registered healthcare professional. This article about the potential benefits of medicinal cannabis might be useful for you to show your healthcare provider if they are not familiar with it.

      You may also find it helpful to contact a support group for medicinal cannabis patients. In the UK there is the United Patients Alliance, and throughout much of the rest of the world there is NORML, who should be able to put you in touch with a group in your area (search United Patients Alliance or NORML followed by your area name).

      This are our pages on medicinal cannabis and medicinal cannabis strains, which you might also find interesting.

      With best wishes,

      Scarlet

  15. This is very much my experience! I smoke for my pain for brittle bones disease (Bruck Syndrome) andhave developed severe rhinitis and now raised itchy white bumps with contact.
    Cannabis helps me greatly for my pain — I do have respiratory discomfort daily as a result of rhinitis. I try to vape most often (no access to edible,) but I do love my joints! I’m worried though, should I be concerned about anaphalyla

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