Cannabis sativa (hemp) is a plant that thrives in diverse environmental conditions. It is used as industrial hemp (low THC cultivars) in manufacturing of yarn, fiber, installation and rope. Hempseed is also touted as a super food rich in protein and promoted for general good health.

Higher THC cultivars are grown for medicinal use generally in the treatment of nausea, anxiety and pain. It is consumed as a recreational drug commonly known as marijuana. It is generally smoked, vaporized or eaten. This industry is growing at a rapid pace particularly with the legalization and relaxation of the laws governing marijuana use.

Can You Really be Allergic to Cannabis?

Allergies are an immune overreaction by the body attempting to protect the respiratory system from outside invaders. The antibodies produced by the body succeed in keeping the perceived foreign invaders out, but also cause the symptoms characteristic of allergic responses. Pollen, the most common allergen, is a powder released by trees, grasses, and weeds to fertilize the seeds of neighboring plants. Mold, somewhat differently, is a spore that grows on rotting logs, dead leaves, and grasses. While dry-weather mold species exist, many types of mold thrive in moist conditions.

Perhaps not so shockingly, given that both these allergens are associated with cannabis, researchers in Belgium recently published an article entitled “Emerging allergens: Cannabis.” The researchers focused in particular on cannabis sativa, one of the two species we all know colloquially as marijuana. They found that the plant can cause a number of allergic symptoms such as allergic rhinitis (hay fever), conjunctivitis (pink eye), skin rashes, and asthmatic symptoms when smoked, inhaled, or chewed. Yikes! On reading that our interest was piqued. This is a thing; an actual thing!

Allergic to Marijuana

Marijuana allergy symptoms

Marijuana allergies have become more common in recent years. Although the plant is known for anti-inflammatory properties, cannabis can cause a number of symptoms if it’s inhaled. If you smoke and you have a weed allergy, you may experience:

  • red eyes
  • watery eyes
  • hay fever
  • runny nose
  • congestion
  • sneezing
  • nausea
  • vomiting

Cannabis allergies can also resemble contact dermatitis if the plant is tampered with or handled. In a 2007 study evaluating marijuana allergy symptoms, a skin prick test revealed that cannabis can cause specific skin irritation. Some of the most common irritations include:

  • itchiness
  • inflamed, red skin
  • hives
  • dry, scaly skin

In more severe cases, an allergic reaction to cannabis can cause anaphylactic shock, a life-threatening condition that causes your blood pressure to suddenly drop and your airways to close. If left untreated, a marijuana allergy could be fatal.

Varying Means of Exposure to Cannabis Allergens

Much like other airborne substances that can trigger allergic reactions (pollen, we’re looking at you!), cannabis sensitization can be influenced by aerobiology. People who live in areas where large quantities of marijuana plants are grown may be especially prone to experiencing allergic reactions to the pollen.

In Omaha, Nebraska, where the plant reportedly grows wildly and commercially, one study looked at cannabis sensitization. This study noted that 61% of 127 patients with allergic rhino conjunctivitis and/or asthma symptoms had a positive cannabis pollen skin prick test reaction.

How is a Cannabis Allergy Diagnosis Made?

Allergic to Marijuana

If you think you might have a cannabis allergy, what’s your next step? What do you do? Where do you go? Well, it’s pretty simple. You book an appointment with an allergist, of course.

The evaluation of cannabis allergies is dependent largely on skin testing. A skin prick test can detect if a person is sensitive to a specific allergen. If sensitive, to protect the body from a perceived threat, the immune system produces a type of antibody called immunoglobulin E (IgE). An allergen-specific IgE blood test is done to check whether a person is allergic to a particular substance. Because IgE antibodies are unique to each allergen, checking for specific variants in the blood can help determine if an allergy is present. The tests are not invasive and tend to produce quick results.

A positive skin prick test to a particular allergen does not necessarily indicate that a person will experience a reaction caused by that allergen. Therefore, healthcare practitioners must compare the skin test results with the time and place of a person’s symptoms to see if they match. If the results of prick tests are negative, they may be followed by intradermal tests, which give allergists more details about what’s causing the underlying symptoms. After either test, the area of the skin is observed for about 15 minutes to see if a reaction develops. The “wheal” (an itchy, red bump) and “flare” (surrounding redness) indicate the presence of an allergy antibody. The larger the wheal and flare, the greater the sensitivity to the allergen.

Although skin testing may seem simple, it must be carried out by trained practitioners with an understanding of the variables and risks of the testing procedure. Extracts for testing are typically created with crushed buds, leaves, and flowers of the cannabis plant. Differences in source material and extraction techniques can introduce significant variability while contaminants and additives in the native allergen can cloud diagnostic evaluation. Consequently, without reliable standardized diagnostic testing options and often poor correlation between testing and true clinical allergy, the importance of patient history in making evaluations is paramount.

Is there treatment?

People who suspect they are allergic to marijuana – whether it’s the pollen in the cannabis plant, mold from storage, or something else – should talk with a board-certified allergist.

The best treatment is avoidance. Certainly people with asthma who count cigarette smoke as a symptom trigger should similarly avoid marijuana smoke.

Prescription and over-the-counter asthma and allergy medications can help prevent and treat symptoms that arise from being around marijuana. These may include albuterol inhalers and inhaled corticosteroids for asthma and antihistamines, intranasal corticosteroids and nasal decongestants for allergies.

Epinephrine auto-injectors should be used as the first line of treatment for anaphylaxis.

Houston allergist and immunologist Ashwini Reddy, MD, representing Allergy & Asthma Network in a recent Fox 26 Houston television interview, noted that allergic reactions to marijuana could develop and worsen over time. “It may not happen the first time you’re exposed to it,” she says.

Currently there is no standardized extract available for marijuana skin tests or allergy shots. People who cannot avoid marijuana due to their occupation – cannabis growers and narcotics officers, for example – should talk with their allergist about other treatment options.

Leave a Reply

Your email address will not be published. Required fields are marked *