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I know one of my grandfather’s first rules of taking me hiking was teaching me to look out for potentially dangerous plants. We would go hiking quite regularly (even when I was a little kid) through the rugged areas of Southern California chaparral. One of the first California native “look don’t touch” plants that he pointed out to me was poison oak. He taught me, “Leaves of three let it be” and every time we would go out and walk he’d be sure to give me a pop quiz. The crazy thing about poison oak is that it is so potent that it can even cause a reaction if you touch something that has touched poison oak. How does poison oak work? This plant uses biologic warfare to protect itself from predators. The “poison” in poison oak is more to do with a human allergic reaction to a chemical that the plant possesses. Urushiol oil is what the poison oak leaves exude when it is damaged by contact. When it comes in contact with skin it causes an allergic reaction also known as “contact dermatitis”  in four-fifths of humans. Usually the allergic reaction it causes is itching and sometimes a rash which can last for 3-10 weeks.

Oak tree and poison oak camouflage

Urushiol can certainly pack a punch just in a touch. Poison oak is not the only plant to use this technique to protect itself. In fact, poison ivy, and plants in the Anacardiacea Family (such as mango and cashews) all use Urushiol as an irritant. So while these plants scream look don’t touch, and most certainly don’t eat,  some of these plants are edible! Mangos and cashews can be eaten and are some of my personal favorites, however not everyone can eat these Anacardiacea family treats. Many people are allergic to mango because of this “look don’t touch” defense mechanism. The skin on the mango usually is the culprit because of small amounts of urushiol on it. In fact it’s pretty much the same reaction you would be having to poison oak or poison ivy. . . only now it’s in your mouth! Not everyone is going to have an allergic reaction. And some key ways to avoid the powerful punch of Urushiol is: rinse, wash repeat, and peel that peel! And for sure start small, don’t gorge

Poison oak is easier to spot when bright red

yourself on mangos even if you love them if you aren’t sure if you are allergic. Urushiol is not to be messed with. The “leaves of three let it be does not apply” doesn’t apply to when you’re looking for mangos or cashews, but perhaps we can think of a funny rhyme scheme to help us. “Allergic to poison ivy?: Mango tree leave it be!” Ok it’s not that great, but it is a start. If you think of a good suggestion on how to remember mangos or cashews as having urushiol please comment below or send us your thoughts!

Check it out: Poison Ivy and Mangos Allergy More on Mango Allergies

Personal Experience with Mango Allergy Read more about Poison Oak

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