Hot Water and Poison Ivy: Does It Help, Hurt or Spread It?

Short answer: Don’t use hot water on poison ivy. To get the oil off, wash right away with soap and lukewarm water, or with a cleanser made for urushiol. On an itchy rash, hot water can feel great for a minute, but the itch comes back and very hot water can irritate the skin. Dermatologists recommend cool compresses instead.

First, what causes the rash

Poison ivy, oak and sumac all contain urushiol, an oily sap. In people who are sensitive to it, urushiol on the skin causes an allergic rash, usually 12 to 72 hours later. The rash itself isn’t the problem you can spread. The oil is.

Washing right after contact

The sooner you wash, the more oil you remove. The American Academy of Dermatology says to wash right away with warm, soapy water, rubbing alcohol or dish soap. NIOSH tells outdoor workers to rinse with rubbing alcohol, a poison-plant wash or degreasing soap and plenty of water, and to keep rinsing so the wash doesn’t dry on the skin.

• Use lukewarm water, not hot.
• Rub for at least 15 seconds, so you lift the oil instead of smearing it around.
• On a crew, keep I.C. Ivy Cleanse foils in the truck so you can wash at the job site, not hours later at home.

Does hot water spread poison ivy?

Hot water doesn’t spread the rash. Oil that’s still on your skin, clothes or gear can spread, so if you shower before the oil is washed off, it can run onto other skin. Wash the exposed areas first, then shower normally.

Why does hot water feel so good on poison ivy?

Many people notice that very hot water briefly stops the itch, and it can feel better than scratching. The relief doesn’t last, and hot water can leave inflamed skin redder and more irritated. It’s also easy to scald skin that’s already damaged. Dermatologists recommend cool compresses and cool or lukewarm baths instead.

Better ways to calm the itch

• Cool compresses: a clean washcloth wet with cold water and wrung out.
• Short, lukewarm baths, with colloidal oatmeal if you have it.
• Calamine lotion, or an anti-itch product used as its label directs.
• Don’t scratch, and don’t break blisters.

I.C. Ivy Relief temporarily relieves the pain and itch of poison ivy, oak and sumac rashes and helps dry oozing and weeping. Don’t use it with any other product containing diphenhydramine, including pills, and don’t use it on large areas of the body.

See a doctor if the rash is on your face, eyes or genitals, covers a large area, comes with fever or swelling, or isn’t improving after a week.

Don’t forget clothes and tools

NIOSH notes that urushiol on tools, gloves, boots and clothing can stay active for up to 5 years. Wash work clothes separately in hot water with detergent; hot water is right for laundry, just not for your skin. Wipe tool handles with rubbing alcohol or soap and water, wearing disposable gloves.

For crews: Block, Cleanse, Relief

1. I.C. Ivy Block before you go in
2. I.C. Ivy Cleanse after possible exposure
3. I.C. Ivy Relief if a rash shows up

Sources: American Academy of Dermatology, How to treat the rash and How can I prevent a rash?; NIOSH, Poisonous Plants and Work.