When we think of an adverse response to cannabis, we typically think of overdoing it due to ingesting too many edibles or smoking too strong a strain. But in some users, cannabis does not agree with their body chemistry. Their immune system rejects the THC or CBD in the cannabis, in turn causing an allergic reaction, which can range from mild to severe.
Cannabis allergies are not all that different from pollen-like allergies to other plants, manifesting in some of the same common symptoms:
Runny or stuffy nose
Sneezing
Itchy, watery eyes
Hives or skin rash
Swelling of the face, lips and/or tongue
Difficulty in breathing
Nausea
Vomiting
Cannabis can also cause skin allergies if the user is handling the plant; the allergy resembling some forms of dermatitis. Skin irritations include:
Itchiness
Inflamed, red skin
Hives
Dry, scaly skin
Additionally, in rare cases, a cannabis allergy can cause anaphylaxis, a severe condition that causes the user’s blood pressure to drop and their airways to close. As this is obviously a life-threatening condition, the user should get medical attention immediately.
A user may not know that they are allergic to cannabis until they try it for the first time. However, they may be more susceptible to a cannabis allergy if they are also allergic to tomatoes, apples, bananas, eggplant, or grapefruit.
If a user suspect that they may be allergic to cannabis, rather than consuming it and hoping for the best, they should check with their healthcare provider ahead of time. The healthcare provider might recommend allergy testing, they might suggest guidance on how to manage the symptoms or they may prescribe medications. In some cases, however, the user may need to avoid cannabis altogether.
Sources: Healthline, Mayo Clinic, Medical News Today