What does poison ivy do to humans?

A Fallow deer doe in Ashdown Forest, Sussex, England.

Poison ivy looks like any ordinary plant out in the wild, so much so that you need some research to identify the plant correctly. But it seems as though some animals appear to be unbothered by the poison oak and ivy plants through their fur coat protection or are immune to urushiol, the plant's oil. But why does poison ivy affect us as humans? And why does the plant cause such harsh allergic reactions?

Why does poison ivy affect us?

If you’ve ever had the misfortune of coming across the plant and getting a bad case of poison ivy rash, you’d think that no living thing should be able to touch, much less ingest, the plant. Surprisingly, poison ivy seems to attract a lot of critters and birds for their berries, and deer even depend on the leaves of the poison ivy plant as a staple food source. Humans aren’t the only ones vulnerable to the plant, though. A good number of primates also seem to be sensitive to it.

We’ve established that poison ivy rash seems to be almost exclusively a human problem. But why exactly just us? The plant and oil itself seem to do no actual damage. However, once the urushiol is absorbed into the skin, it binds itself to the skin cell which alerts our immune system. Yes, poison ivy rash is simply an intense allergy to the plant's oil! Between 80 and 90% of humans are allergic to urushiol.

Ways urushiol can affect us

The oil found in poison oak and ivy (called urushiol) causes rashes, itching, and inflammation. Here are a few ways that urushiol can get in contact with your skin to watch out for:

  • Coming in direct contact with poison ivy plants.
  • Burning the plant (this is extremely dangerous)
  • Coming into contact with tools, clothing, or shoes that have touched poison ivy.
  • Contact with pets who have the oil of the plant on their fur.

Poison ivy affects humans the most, while the rest of the animal kingdom thinks of it as a food source or a minor irritant. And with that, we must handle the plant in any setting with absolute caution.

Fortunately, Tecnu offers a wide range of effective products to help with the damaging allergies and rashes caused by poison oak, ivy and sumac. To help prevent a rash in the first place, use Tecnu Detox Wipes and Tecnu Original on skin, tools, pets, and shoes to limit urushiol binding with the skin.

If a rash has formed, Calagel or Rash Relief from Tecnu will help ease the itch caused by the reaction. Of course, always keep Tecnu products on hand when out on the trail or at home to help combat urushiol on contact.