Parlez-en à votre pharmacien

juin 18, 2020
Q:

It’s that season again. Can you give us a review of poison ivy?

A:

This is a good review for me too! I was hiking the Sussex Bluffs with my retriever today, and I must admit I was on the look-out for position ivy.

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. Upon exposure of urushiol to the skin, an itchy skin reaction, known as allergic contact dermatitis, occurs.   

Symptoms of poison ivy include itchiness, the development of red streaks, or generalized redness of the skin where the plant’s urushiol contacted the skin. The skin may develop blisters that may leak fluid that appears clear, and in severe cases, oozing sores may be present.

What does poison ivy look like?

I found a detailed description of the appearance of poison ivy on the Health Canada website (https://www.canada.ca/en/health-canada/services/home-garden-safety/poison-ivy.html).  The leaves of poison ivy have three pointed leaflets. The middle leaflet has a much longer stalk than the two side ones. The leaflet edges can be smooth or toothed. The leaves vary greatly in size, from eight to 55 mm in length.  

The plant stems are woody and of two kinds. The most common kind grows as a trailing vine, with upright leafy stalks 10 to 80 cm (four to 31.5 inches) high. The second kind is an aerial vine that may climb from six 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 the months of 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 three to seven mm (.12 to .28 inches) in diameter, and they often remain on the low, leafless stems of the plant all winter.

What should I do if I get poison ivy on my skin?

If you think you may have been exposed to poison ivy, then immediately wash your skin. Cold water is preferred because warm water tends to open skin pores, increasing the chance that the poison resin will be absorbed through your skin. Vigorously wash the area in one direction using a cold, damp, wash cloth with dish soap. The sooner you get the resin off your skin, the better. Wash any clothing or footwear that may have been in contact with the urushiol right away. If soap is not available, vinegar (2 tablespoons in one cup of water) or alcohol (1/2 cup to 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 your skin. 

Treatment is primarily aimed at providing symptom relief. Try your best not to scratch the rash because this can lead to skin infection. Topical solutions such as menthol and phenol combinations (i.e., CalamineR 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, 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 beaten path when hiking. If you see a plant you are unfamiliar with, remember the saying: “Leaves of three, let it be”. Avoid letting your dog run off leash when hiking, especially off the beaten trail.  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.

When in doubt, avoid touching an unknown plant until it has been clearly identified.

Dr Kevin Duplisea (PharmD BSc. Pharm, BSc. ACPR) is a pharmacist at Sharp’s Corner Drugstore in Sussex, New Brunswick. His opinions expressed in this newspaper 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. Send your questions to AskYourNBPharmacist@gmail.com.