Escape is impossible: Poison ivy grows in all 48 contiguous states. And its relatives, poison oak and poison sumac, amp up the threat in the West and South. Your concern is urushiol, the oily resin these plants secrete; it sparks an allergic reaction in 70 percent of us. Learn to recognize all three plants, then follow the tips below to minimize your risk and ease the burning itch of an encounter.
Wear long pants and high socks when hiking on overgrown trails.
Banish Fido from the tent if you know he's been running through poison ivy. Your dog's fur can easily transmit the offending oil onto your skin.
Rinse your boots with water or swab them with an alcohol pad. Streaks or patches of resin on your boots can lead to a rash on your hands.
Back home, launder items that you suspect were exposed to poisonous plants. Urushiol on unwashed clothes can trigger outbreaks for up to 5 years.
You have about 10 minutes to remove the urushiol before it binds to the skin. Thoroughly wash the area with slightly warm water (hot and cold water can trap resin in pores) and use soap if you have it. Then wash it again. Tecnu, a product formulated to remove resin without water, also works well. An alcohol sanitizer or prep pad from your first-aid kit is effective on small areas.
Blisters develop within 2 hours to 2 days, depending on your allergic sensitivity. An oral antihistamine (like Benadryl) and calamine or hydrocortisone lotion can offer some relief.
Apply a cool, wet compress to the in-flamed area for 20 minutes. Then allow the skin to air dry. The evaporation is soothing.
Scratch--but gently. Blisters don't contain poison ivy resin, so even if they weep fluid, they won't spread the rash.
The rash will typically clear up in 2 weeks or less, but if it covers 10 percent or more of your body or goes near your eyes, see your physician.