Allergy to Second-Hand Marijuana

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A 6-year-old boy may be the first documented case of allergy to secondhand marijuana smoke. The case study was presented at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting.

When the boy’s severe asthma did not respond to aggressive treatment, his symptoms were linked to the marijuana that some family members were smoking in his home. The boy’s grandmother reported she had used cannabis earlier in her life and had broken out in full-body hives.

“Cannabis allergy can make asthma worse even without direct use,” said allergist Bryce Hoffman, MD, the study’s lead author. “Anyone using cannabis needs to consider that others living in their house who have asthma–particularly children–may be at risk of uncontrolled asthma.” With more states legalizing marijuana, physicians should be alert to the possibility of this allergy in their young patients whose asthma remains uncontrolled despite treatment, he added.