More than half the people in the United States are sensitive to poison ivy, poison oak, and poison sumac. If you are sensitive, you can develop an itchy, blistering rash by coming into contact with these plants.
Whether you are working or just enjoying the outdoors, look out for these plants. Poison ivy is generally found east of the Rocky Mountains, growing as vines or shrubs. The leaves can have either smooth or notched edges and are often clustered in groups of three.
Poison oak is more commonly found west of the Rockies, usually as a small bush but sometimes as a climbing vine. Its leaves are smooth-edged and cluster in groups of three, five, or seven.
Poison sumac is most often found in wet areas of the Southeast. The leaves are generally smooth and oval-shaped, with seven to 13 growing on each stem.
The appearance of each of these plants can vary considerably from region to region, and with the seasons. Even dead plants in underbrush can transmit the toxic oil to your skin.
The rash caused by poison ivy, oak, and sumac is an allergic skin reaction to an oil, called urushiol, which is in the plant. This oil is found in all parts of the plant, including the leaves, stems, roots, and berries.
Exposure to the oil occurs through touching any part of the plants, touching clothing or other objects that have contacted the plants, touching pets or other animals that have contacted the plants, and exposure to the smoke of burning plants.
Exposure to poison ivy, oak, or sumac causes an itching rash that usually appears within 24-72 hours. The rash usually starts as small red bumps, and later develops blisters of variable size. The rash may crust or ooze. The rash may be found anywhere on the body that has contacted the oil from the plant. It can have any shape or pattern, but is often in straight lines or streaks across the skin. Different skin areas can break out at different times, making it seem as if the rash is spreading.
Contrary to popular belief, leakage of blister fluid does not spread the rash. It is spread only by additional exposure to the oil, which often lingers on hands, clothing and shoes (which are often overlooked as carriers), or tools.
See your health care provider if you have Large areas of rash causing significant discomfort, rash on your mouth, genitals, or around your eyes, an area of the rash that becomes infected or drains pus, or if you have a great deal of swelling.
People who are highly sensitive to these plants can get a severe reaction, called anaphylaxis. If you have swelling of the face and throat or difficulty breathing, feel dizzy or faint, or lose consciousness, you may be having an anaphylactic reaction. If you have any of these symptoms, go immediately to a hospital emergency department. Do not attempt to drive yourself; if no one is available to drive you immediately, call 911 for emergency medical treatment. While waiting for the ambulance to come, begin self-treatment measures.
If you are exposed to any of these plants or their oils, wash thoroughly with soap and water as soon as possible. An alternative is rubbing alcohol, which can dissolve and remove the oils from your skin. If you can remove the oil within 10 minutes, you are unlikely to develop the rash.
Symptoms from a mild rash can sometimes be relieved by Cool compresses with water or milk, calamine - A nonprescription lotion, aveeno oatmeal bath - A product you put in the bath to relieve itching, or oral antihistamines such as diphenhydramine (Benadryl) - Caution: these medications may make you too drowsy to drive a car or operate machinery safely.
Nonprescription corticosteroid (eg, hydrocortisone) creams usually do not help.
Do not attempt to treat severe reactions or to "wait it out" at home. Go immediately to the nearest emergency department or call an ambulance.
While waiting for the ambulance Try to stay calm, prevent further exposure to the "poisonous" plant, take an antihistamine (one to two tablets or capsules of diphenhydramine [Benadryl]) if you can swallow without difficulty, if you are wheezing or having difficulty breathing, use an inhaled bronchodilator such as albuterol (Proventil) or epinephrine (Primatene Mist) if one is available.
These inhaled medications dilate the airway., if you are feeling lightheaded or faint, lie down and raise your legs higher than your head to help blood flow to your brain, if you have been given an epinephrine kit for a previous allergic reaction, inject yourself as you have been instructed.
The kit provides a premeasured dose of epinephrine, a prescription drug that rapidly reverses the most serious symptoms, bystanders should administer CPR to a person who becomes unconscious and stops breathing or does not have a pulse, and if at all possible, you or your companion should be prepared to tell medical personnel what medications you take and your allergy history.
Finally, like most allergic reactions, treatment is dictated by the severity of the reaction. Reactions that cover a large proportion of your body, make you uncomfortable enough to disrupt your normal activities, or do not get better within a few days may require treatment with prescription medications.