Poison ivy, oak, and sumac

Dear Alice,

What are the symptoms of poison ivy, poison oak, and poison sumac? Are they treatable with over-the-counter medications OR is a doctor visit required?

Dear Reader,

What an itchy situation! Symptoms associated with poison ivy, poison oak, and poison sumac contact are caused by an allergic reaction to an oily substance produced by these plants called urushiol. Over 50 percent of people experience a reaction to it, resulting in an itchy, blistery rash within hours or up to five days of coming into contact with these fragile, defensive plants. The reaction for most folks will resolve on its own in a matter of weeks and most treatment options to manage symptoms involve do-it-yourself methods. However, there are some instances in which medical care is advised; it depends on the severity of the reaction.

Where might someone come into contact with these furious flora specimens? Interestingly, the three-leaved poison ivy plant is found around most of the United States; it grows as a vine in the Northern and Western states, as opposed to growing in a shrub in the Eastern and Great Lakes states. Poison oak is similar, with three leaves that are a shaped a bit more like oak tree leaves and have fuzzy undersides. These plants can be found across the country, although it's more commonly found in the Western States. Lastly, poison sumac can be found in the Northeast, Midwest, and Southeast, particularly favoring areas that are wet and swampy. It can be distinguished from its harmless sumac brethren by green berry clusters. If someone has the unfortunate luck of brushing elbows (or knees, fingers, legs, or any other body part) with one of the members of this troublesome threesome, look out for the tell-tale rash and incessant itching. They may experience redness, slight swelling, or blisters, as well. Remember that a person can also come in contact with the sap or oil from clothing or pets who have brushed against the plants. A reaction is also possible if the smoke from burning poison ivy, oak, or sumac is inhaled.

As a way of reducing symptoms if contact with these plants is suspected, it’s wise to remove all clothing and shoes that might have been exposed, as soon as possible — preferably while wearing protective gloves. Taking those items through the laundry to remove the oil is a good next step. Infected persons are advised to wash their own skin with soap and water, making sure to also pay close attention to cleaning under the fingernails. Even doing so within an hour of exposure can reduce the severity of a rash. If any pets may have also had contact, donning some rubber gloves and giving them a good scrub-a-dub is a tip-top idea to reduce the risk of secondary exposure. Although the lucky critters rarely react themselves, they can carry the sap on their fur for days, allowing the irritant to be passed it along to their human companions. On the note of secondary exposure, it may be wise to consider what other objects may have come in contact with these rash-inducing plants — cleaning any items such as gardening tools, golf clubs, camping equipment and the like may also be in order to remove the bothersome substance. It's been noted that the urushiol can stay on these objects for years, so getting them clear of this itch-inducing contaminant is key.

Generally, the best treatment is time — the rash and itching will usually go away on its own in one to three weeks. When infected, keeping hands away from the eyes, mouth, and face, and scratching as little as possible is advised, as this can irritate the rash further and may introduce infection. Some non-prescription treatments include calamine lotion, a zinc oxide ointment, over-the-counter (OTC) topical corticosteroid cream, an oatmeal bath soak, or cool compresses may be implemented to relieve the symptoms somewhat. An OTC oral antihistamine may also help; however, it may be that the medication helps those affected to sleep while experiencing symptoms, rather than treating the symptoms themselves.

If there are any of the following result after coming in contact with poison oak/ivy/sumac though, seeking medical care is advised:

  • A severe reaction, including swelling of the throat, tongue, or lips, or difficulty breathing or swallowing
  • Having inhaled smoke from the burning plants
  • Having a fever of over 100 degrees Fahrenheit or signs of infection, such as pus or oozing from rash blisters
  • Rash in your mouth, eyes, or genital area
  • Rash on a large portion of your body or face
  • Symptoms that last longer than three or so weeks or initial treatment that doesn’t relieve symptoms

Ultimately, the decision on how to respond will depend on an individual’s reaction. Here's hoping you’re no longer itching for more information on these plants!

Last updated Mar 22, 2019
Originally published Sep 04, 1998

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