Disclaimer: This article is intended to provide general information about poison oak and its effects. It is not a substitute for professional medical advice, diagnosis, or treatment. If you are experiencing what you suspect may be a severe reaction to poison oak… or are experiencing a severe reaction, it is crucial to seek immediate medical attention. Always consult with a healthcare provider for personalized health concerns and reasons related to your specific medical condition.
Photo by: Mads Engel Hauberg
Poison oak is a hazard most hikers don’t consider when preparing to head out on the PCT, but I learned while backpacking a section in northern California it can have a significant impact on your hiking experience. It was June, and there were places where the familiar plant with its shiny green “leaves of three” crowded the trail. I did my best to avoid touching it and scrubbed with water at the streams we crossed. But within a few days, my skin was reacting. The blistering rash appeared on my legs, then continued up my torso and onto my neck and arms, interrupting my sleep with its intense itching. I had to get off the trail sooner than planned and receive treatment at an urgent care clinic.
Understanding Poison Oak
Recently, I had another reaction to poison oak that lasted over a month despite prescription medications. After this latest encounter with the noxious plant, I was determined to learn everything I could about it in a “know your enemy” sort of way. Despite its name, poison oak (Toxicodendron diversilobum) is not an oak at all but a relative of poison ivy, poison sumac, and cashews. Native to the U.S. West, it ranges from British Columbia through California at elevations below 5,000 feet. Although a good percentage of the PCT is above that elevation, the trail travels through several places where poison oak is abundant. A few locations where you will likely encounter poison oak are around Seiad Valley in northern California and the areas near the Columbia River, especially on the Washington side.
It’s not only the leaves that contain urushiol, the resinous oil responsible for the itchy rash. It is also in the stems and roots, and the oil remains on the plant even if it’s dead. Of course, carefully avoiding touching poison oak is the best way to ensure you don’t have this irritating rash. However, avoiding direct contact with the vegetation won’t completely protect you. The oil sticks to clothing, gear, and animals, putting you at risk if you come in contact with them. The smoke from burning poison oak can also cause serious, life-threatening respiratory tract reactions if inhaled.
Photo by: Jocelyn Songer
Preventing and Treating Poison Oak Exposure
Somewhere between 70% and 90% of people react when exposed to poison oak. This sensitivity can begin at any time in an individual’s life. It seems that all people, given enough exposure, will eventually develop a reaction. If you’ve been exposed to poison oak, the first thing to do is clean your skin as soon as possible. There are several commercially available products formulated to remove the tenacious oil, including Tecnu and Zanfel. Dish soap, laundry detergent, or rubbing alcohol also work. A few brands of wipes are specifically made to remove the oils. These are useful for times when water is limited. Do your best to clean any clothing or gear that has come in contact with it. And avoid wearing your hiking clothes in your sleeping bag.
Once the oil is washed off, the rash cannot spread to other parts of the body or other people. The rash itself, as well as the fluid from the blisters, is not contagious. It may appear to be spreading as new areas pop up on body parts far from where you first got the rash, but it is just the reaction coming on at different rates from the exposure to the oil. Thinner skin, like that at the wrists, neck, and ankles, tends to react before thicker-skinned areas. Another possibility is that there is still urushiol oil on something you are coming into contact with – your shoes, pack, or your hiking partner’s dog, perhaps.
Photo by: Karen deSousa
Symptoms and Duration of Poison Oak Rash
Symptoms typically begin within 12-48 hours after exposure. You may first notice itching that relentlessly increases in intensity, then redness and swelling, followed by blisters that open and ooze clear yellowish liquid. Depending on the individual, the rash usually resolves within about two weeks, although it can take 3-4 weeks or longer.
If you do find yourself with a poison oak rash, there are over-the-counter medications that can provide some relief. Calamine lotion is soothing and helps dry out blisters. Hydrocortisone cream and antihistamines such as diphenhydramine (Benadryl) can help with the itching. Some other ways to treat the itching include aloe vera, baking soda mixed with water, and rubbing a raw cut potato over the affected skin. For severe cases, a medical provider may prescribe oral corticosteroids.
Trim your fingernails short and file them down smoothly. The temptation to scratch is compelling. Do your best to keep the rash and your hands clean, and avoid scratching. Usually, the rash heals on its own without complications. That said, if you develop difficulty breathing, swallowing, or facial swelling, you need medical care immediately. If the rash covers most of your body or is around your eyes, mouth, or genitals, you should also see a medical professional. Watch for signs of infection, such as a fever, thick or colored discharge, or increased swelling and redness. It’s important to get medical care if you develop an infection.
Final Thoughts: Hiking the PCT with Caution
When I now go backpacking in Poison Oak country, I wear long sleeves and pants and carry dedicated sleeping clothes to change into at night. I also have a plastic bag to put contaminated items into. My first aid kit includes Tecnu wipes and cleanser, hydrocortisone cream, and Benadryl. If you have had a severe reaction to poison oak in the past that required prescribed medications, it may be worth requesting a prescription from your provider to have those meds on hand. Just in case!
Whether a thru-hike, section hike or day hike, getting out on the PCT is a memorable experience. I hope that by sharing my poison oak encounter and subsequent learning opportunity, you can avoid adding an exquisitely itchy rash to your list of PCT memories.
About the Author:
Karen deSousa completed the Pacific Crest Trail (PCT) in 2021, a monumental achievement that spanned eight years of dedicated section hiking. Her journey on the PCT varied from shorter 2-mile treks to more extensive 530-mile hikes, with some unintended time off the trail due to life events. Since completing the PCT, Karen has gone on to thru-hike the Arizona Trail and has covered 400 miles of the Colorado Trail, with plans to complete the latter this August.
This winter, Karen transitioned from her nomadic van-dwelling lifestyle to settling on a serene 5-acre wooded property with her partner. She is an ER nurse currently taking time off to explore more creative endeavors.