What it is
Poison ivy, oak and sumac cause an allergic rash from an oil called urushiol. The rash appears 12 to 72 hours after contact, often in streaks where the plant brushed the skin, and it lasts one to three weeks. Blister fluid does not spread it; new patches appearing over several days are areas that got less oil and reacted more slowly.
What you might notice
- Intense itching
- Red streaks or patches
- Bumps and blisters
- Swelling, especially on the face
- New areas appearing for several days after exposure
What we can do on video
- Confirm from the appearance and the story
- Prescribe a steroid cream, or a course of oral steroids for widespread rash or rash on the face or genitals
- Treat itch so they can sleep, and any infected areas
Caring for them at home
- Wash skin, clothes, shoes, gear and pets right away; soap and water within minutes helps most
- Cool compresses and lukewarm oatmeal baths
- Calamine lotion
- Keep nails short and don't scratch blisters open
Be seen in person if…
- Eyes swelling shut, or severe swelling of the face or genitals
- Rash covering a large part of the body
- Trouble breathing or swallowing after being near burning brush
- Fever, pus or yellow crusts
- No improvement after two to three weeks
This information is educational and doesn't replace an evaluation by a clinician. Hugs is not insurance. Treatment is at the discretion of the clinician and limited to what can be safely assessed over video. Reviewed by the clinicians of LPMD Medical Group. Updated 2026-09-17.