Could you have a Cannabis Allergy?

Liz Filmer
15 Oct 2021

Cannabis allergies are on the rise. A 2015 study estimated that around 70% of those who suffer from hay fever could also be allergic to Cannabis.

Cannabis allergies can affect those ingesting Cannabis and those who work with it or are regularly exposed to its cultivation. Allergies have a genetic and an environmental component, meaning as your exposure to a substance increases, so does your risk of developing sensitivity toward it.

As with all allergies, symptoms can vary from very mild to life-threatening in a minority of cases. Typical symptoms, however, include red, itchy, dry or watery eyes, runny nose, sneezing, nasal/sinus congestion, nausea, and physical sickness. 
THC is a recognised potential cannabis allergen. THC levels in Cannabis have risen dramatically in recent years due to selective breeding. Levels in the '60s and '70s stood at around 1-3% whereas today they can be anywhere between 10-30%. Cannabis also contains Pollen, the most common allergen, which is a powder released by plants to fertilise the seeds of neighbouring plants pollen. 
Cannabis allergies can also present themselves as "contact dermatitis" with symptoms including dry, flaky or reddening skin, itchiness, inflammation and even hives!
Mould is also an allergen and can form on Cannabis when exposed to extremes of temperature or high levels of humidity. Common cannabis moulds include Root Rot, Mildew, and Leaf Septoria. Cannabis can also become mouldy if stored carelessly following Harvest. Symptoms from a mould allergy include Allergic Rhinitis, Conjunctivitis, skin rashes, and worsening of Asthma.

When growing, Cannabis can take up dangerous levels of heavy metals like Arsenic, Cadmium, Cobalt, Copper, Lead, and Mercury from contaminated water, soil and fertilisers. These substances can then trigger an allergic reaction when Cannabis enters the body. Symptoms include headaches, nausea, increased risk of respiratory problems and even cancer or organ failure if exposure is extreme and prolonged. To avoid ingesting hazardous chemicals, you should use quality nutrients and additives or go Organic as cheap, low-grade products often contain lower grade heavy metal by-products.

Suppose you're allergic to food with similar protein properties as Cannabis. In that case, you may be at higher risk of a cannabis allergy. Foods with similar allergen properties include Tomatoes, Peaches, Grapefruit, Eggplant, Bananas, Apples, Almonds, and Chestnuts.
So what are the treatments? Well, if Cannabis is still illegal where you live, then a doctor may not care to do much about it! In this case, you could try antihistamine tablets, nasal sprays, inhalers and anti-decongestants. In terms of limiting contact with Cannabis whilst it's growing, wear protective clothing, gloves, and face masks, and have an allergy or asthma medication to hand.
If you are legally using Cannabis, you can have a skin prick test.  If you're allergic, you will show swelling or itching within 15 to 20 minutes. Blood tests can identify antibodies that are specific to a particular type of allergen. 

Due to the lack of standardisation in cannabis legislation, there is limited knowledge, testing, and treatments available. There is a lot to be discovered before we can precisely define allergens, cement testing specifics, and produce clear and effective courses of treatment for those who need it.

Liz Filmer