Q: It’s hiking season again. Can you give us a review of poison ivy?
This is a good review for me too! I was hiking the Five Fathom Hole trail recently and remained on the lookout for poison ivy each time my Golden retriever darted off the beaten path after a squirrel.
What does poison ivy look like?
The leaves of poison ivy have three almond-shaped leaflets. The middle leaflet has a much longer stalk than the two side leaflets. The leaflet edges can be smooth or toothed, and they vary greatly in size, from 8 to 55 mm in length.
Each set of three poison ivy leaflets grows on its own stem, connecting to the main vine. The most common plant stem is woody, and grows as a trailing vine, with upright leafy stalks 10 to 80 cm (4 to 31.5 inches) high. A second kind is also woody but grows as an aerial vine that may climb from 6 to 10 m (6.5 to 11 yards) high on trees, posts, or rough surfaces.
The plant produces clusters of cream-to-yellow-green flowers during June and July. The berries that appear by September are clustered, round, waxy, and green-to-yellow in colour. The size of the berries ranges from 3 to 7 mm (.12 to .28 inches) in diameter, and they often remain on the low, leafless stems of the plant all winter.
You can find a detailed description of poison ivy on the Health Canada website.
What are the signs and symptoms of exposure to poison ivy?
All parts of the poison ivy plant, Toxicodendron radicans, including the roots, contain a poisonous resin called urushiol. When urushiol comes in contact with your skin, a reaction known as allergic contact dermatitis occurs.
Symptoms of poison ivy include itchiness, and the appearance of redness or red streaks on the skin. The skin may develop blisters that may leak fluid that appears clear, and in severe cases, oozing sores may be present.
What should I do if I get poison ivy on my skin?
If you think you have been exposed to poison ivy, immediately wash your skin. Cold water is preferred because warm water tends to open skin pores, increasing the chance that the poisonous resin will be absorbed through your skin. Vigorously wash the area in one direction using a cold, damp washcloth and dish soap. The sooner you get the resin off your skin, the better. You should also wash any clothing or footwear that may have been in contact with the urushiol. If soap is not available, vinegar (2 tablespoons in one cup of water) or alcohol (1/2 cup in 1/2 cup of water) is an alternative.
Most people develop symptoms 24 to 48 hours after exposure. The extent of the reaction depends on the person's sensitivity and the amount of urushiol that comes in contact with the skin.
Treatment is primarily aimed at providing symptom relief. Try not to scratch the rash because this can lead to a skin infection. Topical solutions such as menthol and phenol combinations (i.e., Calamine R lotion) or astringents (i.e., aluminum acetate or aluminum sulfate) may be applied to the affected areas as needed for symptom relief. Skin irritation generally resolves in one to two weeks. Contact your pharmacist or health care practitioner for specific treatment advice.
More severe reactions (i.e. larger affected areas, blistering, skin infection, etc.) require assessment by your physician or nurse practitioner. These treatment options may include corticosteroids or antibiotics (if infection is present). Occasionally, poison ivy can lead to severe and life-threatening reactions. If you experience any swelling of the mouth, tongue, or throat, dial 9-1-1.
What can I do to prevent poison ivy?
Get out and enjoy the New Brunswick outdoors this summer but be aware of your surroundings. Stick to the path when hiking, and avoid letting your dog run off-leash. Although your dog will not get a poison ivy rash, it is possible for him to transfer the urushiol resin from his fur to your skin. If you see a plant you are unfamiliar with, remember the saying: “Leaves of three, let it be.”
Dr. Kevin McLaughlin (PharmD, BScPharm, BSc, ACPR) practices at Kennebecasis Drugs, in Rothesay N.B. His opinions expressed in this column are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment.