Caused by a sensitivity to a resin called urushiol, poison ivy rash occurs when skin comes into contact with the roots, stems or leaves of poison sumac, poison oak and, of course, poison ivy. At least half of all people have a sensitivity to urushiol; however, some develop serious reactions that call for medical attention.
Often, people become exposed to poison ivy unknowingly, when they’re hiking, gardening or doing some other outdoor activity. Once the skin becomes exposed to the urushiol resin, patients may develop the following on their skin:
In most cases, it takes between 12 to 48 hours before symptoms arise. When they do, the rash is typically localized in the area where the skin contacted the plant. That said, patients may inadvertently spread the resin to other parts of the body by touching or scratching.
The vast majority of the time, poison ivy requires no medical intervention. Usually, patients can find relief using over-the-counter corticosteroid creams, calamine lotion, oral antihistamines, cold compresses or cool-water baths containing an oatmeal-based bath product.
When to Seek Treatment
While most poison ivy rashes clear on their own, patients should seek medical help if they notice any of the following:
- Severe or widespread rash
- Rash on face or genitals
- Pus oozing from blisters
- A fever above 100 F
- A Rash that lasts longer than two weeks
When rashes become widespread or result in numerous blisters, a doctor may prescribe an oral corticosteroid, such as prednisone. Because ruptured blisters leave the skin exposed to bacterial infections, a doctor may also prescribe an oral antibiotic.