It's a question we are often asked. Folks that adventure and/or
work in the outdoors think they may have been exposed and want to
know what to expect, while others have broken out and are trying to
determine if their rash was in fact, caused by contact with poison
oak or poison ivy plants.
Before we get into what a poison ivy rash looks like, it is
important to cover what exactly causes the rash. Poison oak, poison
ivy, and poison sumac all contain the same rash-causing allergen
called, urushiol (pronounced: oo-roo-she-all). Urushiol is an
incredibly potent substance found in all parts of the plant
including the leaves, stem, even the roots. A little bit of this
oil goes a long way, it is incredibly powerful!
Exposure can occur from direct contact or indirect contact.
Urushiol does not evaporate, and is known to last on items such as
tools, clothing, gear, fences, pets, etc. for months, even years.
This makes it possible to develop a rash the next time you come
into contact with these contaminated items (also known as secondary
For approximately 85% of the American population, contact with
urushiol causes an allergic reaction called contact dermatitis (the
swelling and irritation of the skin when exposed to an irritating
substance). This is your body's natural reaction to an allergen, in
which your skin alerts your immune system to the presence of an
irritating substance or chemical. Sensitivity to urushiol
develops over time, and is known to increase, as a person incurs
more and more exposures. It isn't entirely uncommon for an
individual to go without a reaction to poison oak or poison ivy for
the first several years of their life, then one day, upon exposure,
develop a rash.
A poison ivy rash can appear anywhere from 24-36 hours after
exposure, and last between 2 to 4 weeks. How quickly symptoms
appear, and the duration of your rash depends on a few factors:
your sensitivity to urushiol, the amount you were exposed to, and
how many exposures to the substance you've had over your
Rashes and what they look like vary from person to person.
Symptoms can include: intense itching, redness, swelling, or
blisters. It is important to never break the blisters, as it can
potentially cause an infection. The liquid that oozes from the
blisters often dries to form a yellow crust-like substance. It's
best to leave the rash uncovered to allow oxygen to aid the healing
process; however, if the blisters ooze excessively, a loose bandage
can be used to cover the area.
Contrary to popular belief, you cannot "cure" a poison oak rash
(or, poison ivy rash). You simply have to let your body run its
natural course. There are however, products you can use to help
alleviate your symptoms (itching, redness, inflammation, etc.) such
as Calagel® Maximum Strength
Anti-itch Gel and Tecnu® Rash Relief™
Spray. If you experience a severe reaction (i.e. swelling of
the face, trouble breathing, etc.) or your rash worsens, or doesn't
improve, seek medical attention immediately.