One February, I went out hiking in an unfamiliar area of the mountains near where I live. I had a great time, but about a few days later, I started getting these itchy, red spots on various places on my skin. I have skin allergies and other problems, so I figured it had to do with something like that. After a couple days of itchiness, I decided to go out and get some calamine lotions. While reading the label, I realized that I might have been exposed to poison oak. I've had a poison oak rash once before and should have recognized the symptoms. This exposure was a little worse than the last time, but still not that bad.
But, I wondered, how did I get exposed to poison oak? I only went off the trail once and there definitely weren't any signs of poison oak that I could see. I had some photos of the area and I still couldn't see any poison oak in them. Usually, what I look for are the leaves that usually grow low to the ground and the base of trees. I talked to someone who was a nurseryman and he told me to look up some sites on Rhus Diversiloba, the scientific name for poison oak. After browsing some sites for a while, I found an exact picture of what I was looking for: poison oak without leaves and it looked just like what I saw while hiking. There were no signs of green on them at all, just some reddish brown stalks that stuck straight up.
Generally, identifying poison oak can be down by looking at the leaves. Poison oak leaves are oval and broad in shape. They are usually grouped in three and a grow at the end of a long, sometimes reddish, stem. The plant will often grow in a large group, together, or they can be spread out along the ground. It likes to live off of other plants, so it's usually found under brush near bushes, rocks and on the base of trees. But, it's much harder identifying dormant poison oak plants. Often, they will grow low on the forest floor, hidden by leaves and other debris, or they grow straight and look like grass that has dried out.
The first time someone pointed out poison oak to me was on a hiking trip with an archaeological group that I was volunteering in. The plant looked pretty harmless and was even fairly out in the open. It was partially covering some morteros with a winding vine that attached itself to a rock. If we had wanted to study that site, we would need some heavy gloves and clothing to remove it. At that time, I hadn't been exposed to it at all, but I was amazed at how close to the trail it grew. A kid or a dog running around the area would have definitely been in trouble.
The second time I encountered it was by accident when I was hiking the Pacific Crest Trail near Ranchita and lost the trail. While I was trying to find it, I had passed through some brush looking for where to pick up the trail. At the time, I was wearing shorts and short sleeves and didn't see the poison oak I was constantly brushing. After about three days, I began to get a rash that was pretty itchy. It wasn't until I went to the doctor that I knew it was poison oak. I used cortisone and calamine lotions and it went away pretty easily. That was actually my first and only exposure up until that February hike.
While out hiking, poison oak should be avoided at all costs. The oil in the plants is similar to oils found in poison ivy and poison sumac, Urushoil and is found in both the leaves and the stalks. So, even if you don't see the leaves on a particular plant, the stalks can still be a problem. So, it's imperative that one knows all parts of this plant in order to avoid it. The Urushoil causes an allergic reaction and each time a person is exposed to the plant, the more sensitive the allergy becomes. Often, a person can touch the plant two or three times before they get a rash. Burning the plant is also very toxic, too, and eating it can be deadly.
The best way to avoid it is to stay on hiking trails. But, even that is not entirely fool proof. Sometimes, the plant will grow very close to trails and walkways. And, Urushiol can be carried on pet hair and clothing. If a pet runs off the trail, rubs against some poison oak, and then touched by someone, the oil can transfer to a person's hands. It can also transfer from the hands to other parts of the body, too. Scratching or touching an affected area within 20 minutes of exposure can spread the oil. After hiking, clothing and pets that have come into contact with poison oak should be washed to prevent repeated contamination.
In southern California, especially in San Diego County, poison oak is extremely common. Mostly, it is found in the less populated areas in the mountains, but still close to a lot of major trails. Most people who are regular hikers in these areas have either seen it or been exposed to it. It's rarely seen closer to the coastal areas and I have never seen it in the low deserts in all my years hiking there. I usually find it in areas where certain types of brush and trees tend to grow. It likes the cooler, more moist, air of the higher elevations.
If one knows that they are hiking around poison oak, they should take precautions. The main precaution being not to go off trail unless one is sure there is no danger. Long paints and sleeves are always useful, but not always practical, especially in summer months. In that case, taking a wet nap or a cloth to wipe off any possible Urushoil as soon as possible can be helpful, but is not a fool proof solution. Taking precautions will make the hike more pleasant. Happy hiking!