Mercy's Dr. Susan Besser & Dr. Michael Billet Share Their Opinion on Patient Exposure to Poison Ivy
July 15, 2020
Dr. Susan Besser, Family Medicine specialist with Mercy Personal Physicians at Overlea, and Dr. Michael Billet, Mercy Emergency Department, were asked their opinion relative to patient exposure to poison ivy. Here are their responses.
How can a reaction to poison ivy be prevented once you are exposed?
Dr. Susan Besser: Poison ivy is a CONTACT dermatitis. That means the rash comes from direct contact to the oil found on the plant (leaves, stems). So, if you wash exposed surfaces within twenty minutes of contact, you are not going to break out. However, you also have to remember to remove all other sources of the oil (it may have rubbed on your clothing, garden tools or pets so you could be re-exposed without even knowing it).
Dr. Michael Billet: The toxin from poison ivy, urushiol, is an oil. So gently washing with soap and water will remove it within 30 minutes of exposure. If left untreated, the rash will usually show up in 12-24 hours.
If you do get a rash how should you treat it to stop the spread?
Dr. Besser: The best way is to avoid further contact with the oil (the irritant), as I said in the last question. Try not to scratch the area or that can cause the body to react further, even if the irritant is gone.
Dr. Billet: Once the rash sets in, the oil has been absorbed and the damage is done. Until then, the oil can spread anywhere with direct contact. Take care when removing boots or clothing that might have been exposed.
What kind of topical treatments work best?
Dr. Besser: Hydrocortisone cream helps. Calamine lotion helps with the itching.
Dr. Billet: The rash will eventually heal on its own; most of our treatments relieve the symptoms. Topical steroids like hydrocortisone and hydrating creams are the mainstays. The goal is to prevent scratching, which can lead to a secondary bacterial infection.
What kind of oral medications can be used?
Dr. Besser: Benadryl is the only over the counter oral medication that helps.
Dr. Billet: Over the counter antihistamines like diphenhydramine (Benadryl) work best to prevent the itch. Oral steroids can help speed resolution, but this is usually reserved to severe cases due to the side effects of the longer courses of steroids used.
How long may the rash last?
According to Drs. Besser and Billet, the resulting poison ivy rash may last as briefly as a week to 10 days but more severe cases may last longer, three weeks or more.
Anything else people should know?
Dr. Besser: If the rash is significant or severe or covers a large part of the body, you may need to see a doctor for other treatments.
Dr. Billet: If a poison ivy plant is burned, the vaporized oil can be inhaled and wreak havoc on the lungs. To play it safe, never burn a vine.