If you’re allergic to poison ivy, you will probably have a reaction to poison oak
People are more likely to come into contact with poison ivy, poison oak, or poison sumac in the summer, when outdoor activities are at their peak. The plants are part of a species called Toxicodendron, which lends its name to the common allergic rash, known as Toxicodendron dermatitis. This annoying skin condition is caused by an oil in the plants that is known as urushiol. Contact with any of any of these plants can result in an irritating, itchy rash. The rash is an allergic reaction that can range from mild to severe. If you have an allergy to one of these plants, you’re more likely to be allergic to resins from the other plants. Similar plant resins are found in Japanese lacquer trees, mango rinds, and cashew shells, and they can also cause an allergic reaction in susceptible persons. Poison ivy doesn’t usually cause a rash on first exposure, but sensitivity develops with repeated exposure in about 85% of people. A rash will occur in up to 90% of people with exposure to an amount less than a grain of table salt.
It won’t spread by scratching
Urushiol can sometimes leave red lines where your skin has come in contact with the substance, but in most cases, the symptoms appear 24 to 72 hours after exposure. A common misconception is that the rash will spread if you scratch it. Scratching can prolong your healing time and may result in a secondary infection, but it doesn’t cause the rash to spread.
Poison ivy is not contagious
Poison ivy is not a contagious rash, but it can be spread by indirect contact with pets, clothing, or other items that have been in contact with the plant. Airborne contact is also possible, since the plants release urushiol particles into the air. These particles can penetrate your skin, or the mucous membranes of your eyes, nose, or mouth. Urushiol can also penetrate your lungs, if inhaled. If poison ivy is burned, the particles of urushiol can become airborne, which might put you at risk of inhalation.
Poison ivy usually lasts up to 3 weeks
Poison ivy symptoms usually last 2-3 weeks, and can include an itchy rash, red streaks, swelling, and blistering. Your skin may be inflamed and may have a burning sensation. New lesions can appear up to a few weeks after exposure. In severe cases, you may need medical attention, but there are a few things you can do to care for a mild rash.
You can get poison ivy from touching your pet
Always wash the area of contact well with mild soap and lukewarm water, as soon as possible. You should also wash anything that might be contaminated by urushiol, including clothing, tools, or pets. Anything that has been in contact with the irritant oil can cause a reaction in a susceptible person.
Relieve the itching with over the counter medications
The itching associated with poison ivy can be unrelenting. Calamine lotion can be useful, and over the counter anti-histamines, like Benadryl, can also help relieve the itch. Cool showers or application of a mixture of baking soda and water can also alleviate itching. A cool compress may relieve irritation during the blistering phase of the rash. An over the counter topical corticosteroid cream is often useful to reduce inflammation, if the skin surface area involved is less than 10% of your body surface area.
When should you consult your doctor?
Any time that you experience respiratory problems after exposure to a plant, seek immediate medical care. Although rare, some people may develop anaphylactic reactions to the chemical urushiol. If you have rashes over large areas of your body, or if you’ve had a rash for longer than ten days, you should consult your doctor. It’s also important to consult a physician if you have a rash that is located near the yes, lips, throat, or genitals. You may need an oral corticosteroid or an injection of a corticosteroid to stop the inflammation. Poison ivy can become infected from scratching, so call your doctor if you notice pus or if the affected area becomes painful. Fever is another sign of infection that should prompt you to seek professional help.
Prevention is the best strategy
Prevention is important in the summer. There is an old saying: “Leaves of three, let them be.” This should prompt you to avoid contact with plants that have the three-leaf structure associated with poison ivy or poison oak. Even dead plants can have active urushiol. Cover up when you’re outdoors, and take sensible precautions to avoid exposure to Toxicodendron dermatitis. If exposed, wash thoroughly for twenty to thirty minutes before urushiol oil can penetrate your skin. If you have a severe rash, call your doctor. You may need a high-potency steroid cream, an oral corticosteroid like prednisone, or an injection.