(KPLR) – The recent beautiful weather has encouraged many of us to spend a day in the woods or doing yard work. Some of us developed a streaky, red, bumpy rash that turns into weeping blisters. Poison ivy and related plants are a common problem that can be easily treated and even prevented by learning to identify them. Dr. Sonny Saggar spoke with Christine Buck about this common problem.
You can connect with Dr. Saggar, the Medical Director at St. Louis Urgent Cares, and ask him any questions you like.
What are poison ivy, oak, and sumac?
Poison ivy, poison oak, and poison sumac are plants that can cause a nasty skin rash called ‘allergic contact dermatitis.
When they touch your skin. The red, uncomfortable, and itchy rash often shows up in lines or streaks, often with fluid-filled bumps (blisters) or large raised areas (hives). It is the most common skin problem caused by contact with plants (plant dermatitis).
What causes a poison ivy, oak, or sumac rash?
The rash is caused by contact with an oil (urushiol) found in poison ivy, oak, or sumac. The oil is present in all parts of the plants, including the leaves, stems, flowers, berries, and roots. Urushiol is an allergen, meaning the rash is actually an allergic reaction to the oil in these plants. Indirect contact with urushiol can also provoke a reaction like this.
For example, when you touch clothing, pet fur, sporting gear, gardening tools, or other objects that have come in contact with one of these plants. Urushiol does not cause a rash on everyone who gets it on his or her skin. Some people never get a reaction and some people get poison ivy reactions some years but not other years.
What are the symptoms of the rash?
The usual symptoms of the rash are:
● Itchy skin where the plant touched your skin.
● Red streaks or general redness where the plant brushed against the skin.
● Small bumps or larger raised areas (hives).
● Blisters filled with fluid that may leak out.
The rash usually appears 8 to 48 hours after your contact with the urushiol. But it can occur from 5 hours to 15 days after contact with the plant. The reaction usually takes more than a week to show up the first time you get urushiol on your skin, but the rash develops much more quickly (within 1 to 2 days) after later contacts.
The rash will continue to develop in new areas over several days but only on the parts of your skin that had contact with the urushiol or those parts where the urushiol was spread by touching.
The rash is not contagious. You usually cannot catch or spread a rash after it appears, even if you touch it or the blister fluid, because the urushiol will already be absorbed or washed off the skin. The rash may seem to be spreading. But either it is still developing from earlier contact or you have touched something that still has urushiol on it.
The more urushiol you come in contact with, the more severe your skin reaction. Severe reactions to smaller amounts of urushiol also may occur in people who are highly sensitive to urushiol. Serious symptoms may include:
● Trouble breathing – although this is not common with Poison Ivy
● Swelling of the face, mouth, neck, genitals, or eyelids (which may prevent the eyes from opening).
● Widespread, large blisters that ooze large amounts of fluid.
Without treatment, the rash usually lasts about 10 days to 3 weeks, but for some people, the rash may take up to 6 weeks to heal.
How is the rash diagnosed?
The rash usually is diagnosed during a physical exam. Your doctor or Nurse Practitioner will examine the rash and ask questions to find out when you were exposed to the plant and how long it took the rash to develop. If you are not sure whether you were exposed to a plant, he or she will ask about your outdoor activities, work, and hobbies.
How is the rash treated?
First strip off your clothes and place them in a plastic garbage bag to prevent them scattering the Urushiol oil elsewhere, if possible. Get into the shower as quickly as you can and wash your skin with cool water and a soap that does not contain oils. Washing the resins from poison plants off of your skin within 30 minutes of exposure can prevent most allergic reactions.
You can apply rubbing alcohol to your skin to dissolve the poison ivy or poison oak oils. If you’re outdoors in the woods when you’re exposed to poison ivy or poison oak, then you can rinse your body off in a running stream.
Make sure to scrub under your fingernails with a toothbrush in case any oil from the plants is deposited beneath them. Remember to throw the toothbrush away after you’re done. It’s no good for anything.
Most poison ivy, oak, or sumac rashes can be treated successfully at home. Initial treatment consists of washing the area with water immediately after contact with the plants. To relieve symptoms, use wet compresses and take cool baths. Nonprescription antihistamines and calamine lotion also may help relieve symptoms. Moderate or severe cases of the rash may require treatment by a doctor or Nurse Practitioner, who may prescribe corticosteroid pills, creams, ointments, or shots (injections) .
How can I prevent the rash from poison ivy, oak, and sumac?
● The best way to prevent the rash is to learn to identify and avoid the plants. When you cannot avoid contact with the plants, heavy clothing (long pants, long-sleeved shirt, and vinyl gloves) and barrier creams or lotions may help protect you.
● Poison ivy has 3 shiny green leaves and a red stem. It grows as a vine, typically along riverbanks.
● Poison oak grows as a shrub and has 3 leaves like poison ivy. Poison oak is typically found on the West Coast of the U.S. although there is an East Coast variety.
● Poison sumac is a woody shrub with 7 to 13 leaves arranged in pairs. It grows in abundance along the Mississippi River.