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Poison Ivy

Welcome to Bloomington. Beware the leaves of three…and let them be.

It's extremely common in Monroe County and within the IU Campus. You'll see its vines growing on trees, rock walls, and buildings. It can even take over small bushes and shrubs. You'll recognize it by three vaguely mitten shaped leaflets, all joined to a common stalk. Sometimes, the stems are slightly reddish. In mid-summer, it sprouts grape-like clumps of greenish to off - white berries. In the fall, the leaves can turn an attractive orange-yellow or red...inviting to the touch, but please avoid temptation! There are two other less common, yet locally found, plants of the same family and genus with similar capability to cause contact dermatitis that that you should be aware of…poison oak and poison sumac. They are different in appearance than poison ivy and less commonly seen in the Bloomington area, but as potent. Learning to identify all three is a worthwhile investment of time.

The "poison" in poison ivy comes from an oily sap containing the allergenic compound urushiol. The sap is found in essentially all parts of the plant including the leaves, stems, vines, roots and berries. Bruising, cutting, breaking or burning any part of the plant readily releases the sap, which clings to your skin, under fingernails, to pet and animal fur, yard tools, and clothing.  You can readily get contact dermatitis from touching those items, even weeks later. Inhalation of smoke from burning poison ivy can cause reactions to nasal passages, the oral cavity and even airways of the lungs. Since the sap remains on the plant long after the leaves fall off, poison ivy reactions can occur during winter, as well other warmer seasons of the year. Poison ivy dermatitis affects all ethnicities and skin types, and most geographical regions in the United States are inhabited by some variety of the plant.

Poison Ivy Symptoms

Approximately 50% of persons who contact poison ivy will develop symptoms. The symptoms vary in severity from person to person. Urushiol (the allergenic component of the sap) can begin to penetrate the skin within 5-10 minutes of contact. Poison ivy rash can appear in as little as 4 hours or as long as 2-3 weeks after exposure. Generally, you'll see the first blisters within 1-14 days. Symptoms include:

  • Red, swollen, itchy skin with a rash that can be widespread depending on contact areas. Often the rash is streaked or linear in the pattern of contact w/the plant’s sap.
  • Blisters that break and ooze (the fluid from the blisters does not cause further spread of rash to you or others).
  • Secondary skin infection can occur from excessive scratching which will cause pain, increased redness and a potential change in the nature of the drainage from clear to pus like.

Poison Ivy Prevention

The best means of prevention of poison ivy is avoidance of contact.  Learn to recognize the appearance of local urushiol containing plants and keep yourself and pets from coming in contact with them. Avoid walking too closely to discharge from mowers, bush hogs, and weed trimmers. Do not expose skin or lungs to smoke from brush pile fires. Wear protective clothing and heavy vinyl gloves (rubber or latex gloves are less effective) if you know you are likely to come in contact with poison ivy through work or recreational activity, or care for pets that are free to roam wooded or weeded areas. Some benefit with use of commercially prepared barrier creams such as Ivy Block (Bentoquatam) has been documented. Once, however, the sap gets on your skin, it soaks in quickly. If you wash with mild soap and cool water within 10-20 minutes of exposure, you may be able to prevent or at least lessen severity of the rash. Even washing up to one to two hours after exposure may be somewhat helpful. Avoid overly vigorous scrubbing of skin which can worsen impending dermatitis. Fingernails should be washed carefully to remove resin that may remain under the nails and provide a means of ongoing contact w/body parts for weeks to come.

Poison Ivy Treatment

Once the itch arrives, further washing to remove the urushiol oil is not likely to help. Keep in mind the itch and rash can occur to any part of the body with which contaminated hands, clothing, pets, etc. have come in contact…yes, even there.

There are a few things you can do to ease that awful itching. Try these tips:

  • Take cool baths and showers, because heat causes the rash to itch and swell more.
  • Cool Domeboro or Burow's Solution soaks/compresses can be soothing
  • Compounds containing menthol and phenol, such as Calamine Lotion, can temporarily lessen itch
  • Over the counter topical steroids, such as 1 % hydrocortisone cream may of benefit. Avoid repeated use to sensitive skin areas of the face, genitalia, or skin fold areas, or any use to mucosal areas or around the eyes, and use for greater that 14 days to normal skin areas.
  • Treat broken blisters with gentle soap and water hygiene and, if needed, light non-adherent bandages to prevent infection.
  • Avoid use of topical products containing benzocaine, neomycin, bacitracin, or antihistamines, as they possess their own allergenic potential. 
  • Since the itch from poison ivy is not caused by histamine release, second generation antihistamines such as Claritin, Clarinex, Allegra, or Zyrtec, are of little use. First generation antihistamines such as Benadryl have some potential for relief, largely through side effects of sedation, which at least allow for sleeping despite the itch. Driving, alcohol / recreational drug use, and use of any other known sedating medications should not be mixed w/the use of first generation antihistamines.
  • Consider treatment at the IU Health Center for cases of suspected poison ivy or other types of contact dermatitis, as there are prescription regimens which can greatly impact the speed with which your symptoms can improve.