Symptoms usually appear 12 to 48 hours after exposure, beginning with itching, followed by a red rash. There may be swelling and vesicles, which may break and drain serous fluid. The blisters and rash commonly appear in streaks, where the plant contacted the skin. After about a week, the reaction enters a sub-acute phase and the blisters begin to dry.
Severe itching is experienced throughout the reaction, making it difficult to sleep. Fact: Poison ivy is not contagious. Poison ivy is an allergic reaction to urushiol the toxin found in poison ivy, oak, and sumac plants.
The only way to develop a case of poison ivy is through direct contact with the plant, or by touching a fomite, such as clothing or gardening tool, that has been contaminated with urushiol. Fact: Scratching will not move the rash from one area of skin to another. The rash can appear on different parts of the body at different times. Urushiol penetrates thin skin easier than thick skin, therefore the onset of symptoms will occur more quickly on the facial skin than on the forearm.
Likewise, an area with a large urushiol exposure produces a rash more quickly than an area with a small exposure. Patients should avoid scratching to help reduce the chance of a secondary infection caused by bacteria from the fingernails. Treatment centers on controlling the symptoms of poison ivy, oak, and sumac reactions by using prescription strength steroid creams, calamine lotion, baths with colloidal oatmeal, and wet-to-dry dressing changes.
These treatment options provide temporary relief, and have to be applied repeatedly throughout the 16 to 18 day or longer allergic reaction. Another nonprescription treatment is Zanfel, a patented soap mixture of ethoxylate and sarcosinate surfactants that removes urushiol from the skin.
A randomized, double-blind, study of 24 urushiol-sensitive adults demonstrated that an objective score combining redness, skin firmness, and blistering was reduced 48, 96, and hours after exposure to urushiol in patients who washed with Zanfel vs.
In another randomized, double-blind, placebo-controlled study of 20 urushiol sensitive subjects, Zanfel was found to effectively treat allergic contact dermatitis, which was experimentally induced with naturally occurring urushiol.
This study also found that Zanfel is effective as a post-exposure prophylaxis measure. Most people require only one use to relieve itching and put the body in a position to heal.
Systemic steroids have been the standard of treatment for severe cases of poison ivy, oak, and sumac. Steroid dose packs should be avoided, as they do not contain a high enough dose or a sufficient duration of time.
And it can remain an active irritant for months. Long after the initial exposure and after your rash has gone away, you can get red and itchy all over again by touching something that still has the sap on it. It's a common misperception. But poison oak and poison sumac have never been documented by botanists as growing in the state of Iowa, according to the Iowa Department of Natural Resources.
There are plants, even oak and sumac species, that look similar but are not poisonous. Some people mistakenly think that a different-looking species of poison ivy is actually poison oak or poison sumac.
Poison ivy, however, is prevalent in the state. It can be seen creeping along a hiking path or up the trunk of a tree in your own backyard. It's everywhere! Poison ivy is the most common cause of contact dermatitis in the United States. If you leave the state on a summer vacation, you may also run into its cousins. Poison sumac is primarily found in the eastern part of the country, as well as Minnesota, Wisconsin and Illinois.
Poison oak is native to the West Coast and the Southeast. If you'll be spending a lot of time outdoors in these areas, the Centers for Disease Control and Prevention mapped out the geographic distribution of poisonous plants so you know what to avoid. Most cases of poison ivy rash aren't serious. You can treat the rash and relieve the itch with home remedies. Rinse your skin immediately! Whether you know you touched poison ivy or didn't know until you saw a rash, rinse the exposed areas to wash away the oils and prevent the poison ivy rash from spreading to other areas of your body.
Don't stop there. Wash everything else that may have come in contact with the poison ivy oil — clothes, pets, tools, door handles and any other hard surfaces. That is of cold comfort for anyone who has ever had pus-filled blisters between their toes or under their wedding ring… You can use calamine lotion for some cooling and itching relief. When things become unbearable, patients often come to us. At Peraza Dermatology Group, we prescribe topical steroids to manage the poison ivy quickly and effectively.
Make an appointment to discuss your symptoms and have your poison ivy questions answered. The culprit: the urushiol oil. Here are some tips to avoid it.
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