What You Need to Know About Poison Ivy Rash

Greenery jungle path with poison ivy alongside.

If you live in the United States, you’ve very likely to have personally experienced poison ivy, or know someone who has. This poisonous plant can be found in every state in the US except for Hawaii and Alaska, and roughly 85% of people will experience an allergic reaction when they come into contact with it. 

This means that most people already have at least some baseline knowledge about poison ivy, but many still don’t know how to identify poison ivy rash or how to treat it once it occurs. 

Key Facts

As we mentioned, poison ivy is a toxic plant found around the entire continental United States. It can be identified by its three oval-shaped leaflets with jagged “teeth” along their edge, the three leaflets being connected to a thin stem. Every part of the plant from leaf, to stem, to root is coated in a layer of waxy oil called urushiol, and it’s this oil that brushes off on human skin and causes the famous allergic reaction when a person comes in contact with poison ivy. 

It’s important to note that human skin usually needs to come in contact with urushiol once or twice before becoming sensitized to it, and most people will not experience any symptoms at all the first time they encounter poison ivy. This can result in some people believing that they’re immune, only to break out in a rash when they encounter the plant a second or third time. 


Once sensitized to urushiol, contact with poison ivy will result in a rash on the area of the body that was directly exposed to the plant. Symptoms include redness, itching, swelling, and potentially blisters, all generally appearing in straight lines due to the way the plant will naturally brush against skin. Generally, the rash will appear 12 to 48 hours after contact and goes away naturally within a week or two, with the severity of the rash depending on exactly how much urushiol was exposed to the skin. 

It is worth noting that the rash itself is not contagious - it’s impossible to spread a reaction from person to person by touching a poison ivy rash, although it is possible to spread by touching urushiol oil residue that’s been left on clothing, pet fur, outdoor tools, or other items.

While it’s almost never necessary to go to a doctor for poison ivy rash, there are exceptions. You should always seek medical help if:

  • The rash doesn’t go away after a week or two
  • The rash spreads to a large area of your body
  • You have blisters that ooze pus
  • The rash is on your face or genitals
  • You have a fever of over 100 F
  • You experience shortness of breath or trouble breathing

Prevention and Control

The simplest and perhaps best form of prevention is knowing what poison ivy looks like and taking pains to avoid it. However, keeping a vigilant eye isn’t always a guarantee of safety, and you can hedge your bets by wearing long clothing that leaves little or no skin exposed, or by cleansing with a product designed to remove urushiol as soon as possible after exposure. 

It’s also important to control and remove poison ivy if you notice it growing around your home or property, although this must be done carefully! Cutting poison ivy exposes its highly allergenic sap, and burning the plant is even worse since the urushiol is directly released into the air via the smoke. If inhaled, this smoke will cause swelling and irritation of the esophagus, leading to difficulty breathing and potentially death. The best option for removal is to use a specialized herbicide after consulting with professionals.


A reaction can be completely avoided if you are lucky and are able to wash the urushiol off of your skin with soap and water, or, a specialized cleanser within the first 8 hours of contact with your skin; the sooner the better. However, most people will have to find ways to deal with an uncomfortable rash. 

No matter what, if you’ve come in contact with poison ivy you should wash the affected skin and the clothing worn when you were exposed. You don’t want to infect yourself or others with urushiol residue on clothing, and any excess oil you can remove from your skin via washing will be helpful. 

Beyond simple washing, itchiness can be treated by taking an over-the-counter antihistamine, by applying calamine or hydrocortisone cream to the rash, with frequent washing and bathing, or by applying a cool, wet compress to the affected area. 

It’s vital to mention that scratching the itchy area should be avoided as much as possible. Scratching will generally worsen and prolong the effects of the rash, and can even lead to infections if you break the skin. 

Using the Best Products

At Tecnu, our goal is simple: to create innovative products that help our consumers solve a serious problem. 
Tecnu offers the industry’s best treatments for poison ivy, poison oak, and poison sumac. Our Original Outdoor Skin Cleanser and Extreme Poison Ivy Scrub help wash away the culprit urushiol.