What is the irritant in poison ivy?

Answer 1

That the plant's urushiol oil is extremely irritating is the reason for the itching that poision ivy (Toxicodendronradicans) causes.

Specifically, the plant's oil actually is not poisonous. Instead, it is an allergen that brings on an allergic reaction in humans, but not wildlife. At the same time, it is an allergen that also may have fatal consequences when the face, the neck and throat, and the respiratory tract are involved.

Answer 2

Your immune system is going crazy once your body has come into contact with the oil from the plant and the itchy part is the healing/reaction form the rash. Itching it will not cause it to spread and you can not past it along to others however, it can become infected and infact worsen.

Answer 3

Take it from someone who had tried EVERYTHING -- from weekly injections to prescription drugs to over the counter medicine, and all kinds of baths, solutions, wet packs, and home made remedies. Not much success with any of them, while being always the kid sent home from camp because of poison ivy, until 30 years ago when the secret of an old home remedy was shared, and it turned out to be the best cure. This came from a very old farmer in Indiana who learned it from his mother:

Put the thick "juice" you get when you break open a fresh stalk of rhubarb onto the rash. Just break it open and rub it on. It will kill the itch immediately. The rash will dry up and just disappears before you can believe it. This has worked for many people over the years. Some have reported success with even using thawed frozen rhubarb (and they said if you use it while still cool, but no longer frozen, it is heavenly). I have not myself tried using the frozen rhubarb, but nurse friends of mine have.

Answer 4

Urushiol oil is the irritant in poison ivy (Toxicodendron radicans).

Specifically, the resin is a known irritant to most humans. Wildlife can come into contact with the irritant without showing any allergic reactions. Domesticated pets cat/dog once exposed may or may not exhibit symptoms of poison ivy/oak allergy. Once a human comes into direct contact by touching a previously urushiol exposed item afterwards, may themselves exhibit allergic reactions.

Answer 5

Poison ivy contains an organic toxin called urushiol which elicits an allergic reaction. As noted in the related question:

Urushiol is an organic oil toxin found in plants of the Family Anacardiaceae (e.g. poison oak, poison ivy, and poison sumac). It causes the allergic skin rash on contact, known as urushiol-induced contact dermatitis.

Answer 6

A reaction to poison ivy requires contact with the urushiol oil. The oil may be in its liquid form, or as vapors. The oil is so strong that where it has grown may contain residues of the oil even 1-1/2-2 years later.

Answer 7

Poison ivy has oils on its leaves. Contact with these oils causes a delayed rash reaction on most human skin.