This was an individual case analysis study published in the journal Allergy, Asthma, & Clinical Immunology in May 2021. It examined a user of cannabis flower that reported an allergic reaction to a specific cultivar of cannabis.
After exposure to one cultivar, the 31-year-old male developed a severe local reaction involving "bilateral periorbital edema", which is swelling around the eyes. Allergy tests were performed on 5 cultivars of cannabis flower, and the patient returned positive results for allergy to three of the cultivars, but NOT the other two.
The patient tested positive for allergy to Blue Dream, Sweet Island Skunk, & Blueberry Haze, but tested negative for allergy to Blue Moonshine and Sweet Skunk. "This case report outlines the variability in different strains of cannabis and stresses the importance of further research into cannabis allergen identification."
Unfortunately, the paper does not examine the certificates of analysis of the five cultivars to determine the differences in cannabinoids, terpenes, and flavonoids. The authors spend time talking about Indica vs. Sativa which we all know is not a reliable predictor of consistent active ingredients, since almost all popular cultivars are hybrids.
Everyone has different allergies, so this is not meant to be a guide for others. It is a reminder that everyone is different, and what works great for one person, may not work well for another.
The link to the study report is here.