The stuff causes severe allergic reactions. Many trees have it at sap, said the dermatologist. He was writing a prescription for Burows Solution and some antihistamines. He rattled off some incomprehensible botanical names as he did. I did understand Sumac because my uncle had once told me about it. The doctor was referring to the other trees, shrubs and vines that have urushiol in them.

I was back from a long trekking trip in North America and caught a very irritating rash during a campout. I’d thought I’m an experienced outdoorsman but had somehow forgotten the childhood warning leaves of three, let it be.

Call it poison oak or poison ivy, the stuff is quite volatile. The doc went on to tell me that people have died after eating poison ivy by mistake. Others have thought that they can burn it safely in a campfire. The fact is that burned poison oak and poison ivy delivers its urushiol through the smoke and into the lungs. People have had terrible lung problems because of that. Some have even died. If you’re an asthmatic and get a dose of poison icy smoke, you are in deep trouble.

If you find the typical inflamed red lines and blisters on your skin after a walk through the woods, you need to take action immediately. Apply cool compresses to the affected area. Use any kind of astringent you have around the house too. Burows Solution is the time-tested treatment, so use it if you can get it. You can also have a fan blowing over the compress to help in cooling the area. An ice cube works very well if one is available.