poison oak and ivy left arm

When I was eight, I was on a hike with my family in northern California when my older brother decided he didn’t want to hike anymore, so he grabbed a handful of poison oak and smeared the leaves over his arms. Naturally we had to turn around and head home after that, so my brother got his way–but at a hefty price.

So whether you want to avoid poison ivy or you want to manipulate your mother into taking you home, here are some helpful tips to identify the noxious plant.

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How to spot the plant

The easiest rule to remember is “Leaves of three, let it be.” Poison oak and ivy have clusters of three leaflets. The leaf color can range from green to orange to purple-red.

Poison oak

Poison oak is dull green to reddish color and has a hairy surface. The shrub appears in the northern and western US (American Academy of Dermatology). It is typically found in shady areas.

Poison ivy

Poison ivy has hairy vines and a smooth surface. The vine appears in the eastern and southern US.

The Rashes

Both contain oils that cause itching and blistering on the skin. The oils are on all parts of the plant–the stem, leaf, and roots–so touching any part of the plant can cause a rash. Even touching a surface or a pet that has come in contact with the plant can create a reaction.

How to treat the rashes

The rash caused by these plants is called Contact Dermatitis, which is an itchy and red rash that can form blisters or bumps. It usually does not appear right away but may take a few days. A clue that your rash is from an external allergen is that some of the papules and vesicles may be arranged linearly–evidence of a leaf brushing against your skin.

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Luckily, there are at home remedies for when you do get poison oak on your skin–intentionally or not. These are appropriate only for very mild cases of poison ivy.

  • Wash your skin with soap and water to remove the oil and prevent spreading.
  • Wash your clothes to prevent another rash.
  • Don’t scratch your skin to prevent infection and spread of the rash elsewhere.
  • Apply over the counter hydrocortisone to help with itching and redness.
  • Apply a cool washcloth to itchy areas.

The rash should go away within two weeks. Moderate or severe poison ivy requires a trip to the dermatologist for stronger topical and oral steroids.


If you’re concerned about coming into contact with poison ivy while on a hike or just walking outside, wear pants and long sleeves to protect your skin. If you see poison oak, the best idea is to leave it alone. Trying to remove it yourself will put you at risk for a serious rash. Do Not attempt to burn the plant because that will release the oils into the air which can land on your skin or get into your lungs.

Learning what the plant looks like is the best way to avoid an unpleasant rash.

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