Lice treatments
Another allergen is lice treatment, as it contains pyrethrins, a substance extracted from chrysanthemum flowers. Pyrethrins are known to kill live lice, but they can also trigger allergic reactions in humans, especially if they’re already allergic to chrysanthemum or ragweed.
Pine trees
The oily allergen in pine trees can cause allergic reactions in humans, with symptoms similar to poison ivy. Urushiol is the main ingredient found in both pine trees and poison ivy.
According to Dr. Richard Lavi, of the Allergy Asthma & Sinus Relief Center in Twinsburg, Ohio, “It’s usually a contact allergy, so you have to touch it to be affected, but it could be airborne if you burned a lot of pine needles, though that’s unusual.”
Make sure to also check: 16 Science Mysteries Scientists Still Don’t Have An Answer For.