Common Questions About Poison Ivy

Published January 1, 2022

hands with medical gloves inspecting a rash

How fast do symptoms show up?

It’s the oil in poison ivy leaves, roots, and stems that causes the rash and itching. Once the oil gets on your skin, it might be 4 hours to 4 days before you see anything. Symptoms hit their peak 1 to 14 days after you come into contact with the oil.

I think it’s spreading. Is it spreading?!

No. It’s just that your body can be slower to react in some areas, so the rash shows up later. That can happen wherever you have thicker skin or get less oil on you.

How do I treat poison ivy?

First of all, be sure to go easy when you clean areas of your body affected by poison ivy. Use mild soap that doesn’t have scents or perfumes (eczema soaps can be great).

For the itchiness, try calamine lotion or an oatmeal bath. If it’s really bad, use an over-the-counter steroid cream, as directed on the label.

If your symptoms keep you up at night, take 25 mg to 50 mg of Benadryl. If sleep isn’t a problem, take 10 mg of Zyrtec during the day.

Do I need a prescription or anything?

Not usually. The medications and treatments we suggest above should do the trick. The only time you need something stronger is if you get it on your face or genitals (private parts). In that case, the swelling — not the rash itself — can cause problems and we’d prescribe a steroid you take by mouth. But those steroids are strong and can have side effects, so you only get them when you really need them.