May 04, 2023 | Black & Kletz Allergy
It is the Spring now and people will be spending a lot more time outdoors. Activities such as hiking, gardening, landscaping, golf, and picnicking tend to pick up in the Spring when the temperatures are warmer and these activities are generally enjoyed until the late Fall in the Washington, DC, Northern Virginia, and Maryland metropolitan area, when the temperatures become cooler. These outdoor activities as well as other outside happenings may predispose an individual to coming in contact with poison ivy, poison oak, and/or poison sumac. These plants are well known for causing an itchy rash when the plants come in contact with a sensitive individual. The itchy rash can occur from touching any part of the plant including the leaves, berries, flowers, stems, and/or roots, whether the plant is living or dead. In some individuals, coming in close contact with anything that has touched the plants, (e.g., shoes, sneakers, clothing, garden tools, lawn mowers, fur from animals) can also spread the agent that is responsible for causing the itchy rash.
The agent responsible for causing the itchy rash is a chemical called urushiol. It is important to note that all parts of these 3 plants contain the same oily pale-yellow liquid resin called urushiol. As stated above, it is this contact with the urushiol that is responsible for causing the rash. When an urushiol-sensitive individual comes in contact with the urushiol, an allergic reaction takes place. This allergic reaction occurs on the skin which results in an itchy rash. The rash that is caused by poison ivy, poison oak, and/or poison sumac is classified as “contact dermatitis.”
The itching and rash can vary in severity from individual to individual and range from a mild rash to a severe rash. The symptoms of the cutaneous allergic reaction may include itching, linear red streaks (which characteristically follows a straight line pattern where the plant brushed up against the skin), red bumps of varying sizes, and/or blisters filled with fluid. Occasionally, the rash can become secondarily infected, which is usually due to scratching. Rarely, an individual may be so highly sensitive that angioedema (i.e., swelling) of the throat, face, lips, eyes, and/or neck may occur. If this type of swelling occurs, it can manifest itself as difficulty swallowing and/or difficulty breathing which can be very serious as it may lead to unconsciousness. Individuals who develop such severe reactions should go immediately to the closest emergency room for treatment.
Usually, the symptoms of poison ivy, poison oak, and/or poison sumac begin between 24-48 hours after contact with the plants. Occasionally, it may take a longer period of time to develop symptoms, particularly if it is the first time that the individual has a reaction. The rash typically lasts about 2-3 weeks in duration, but can persist much longer in some sensitive individuals.
A few common fallacies should be pointed out about poison ivy, poison oak, and poison sumac. First of all, this type of contact dermatitis does not actually spread by itself. In order to develop a rash, contact with the urushiol liquid is necessary. Thus, the only way the rash is transported to other areas of the skin would be from spreading the oily urushiol from one area to another by way of one’s fingers. It is actually the urushiol being transported from one area to another that causes the contact dermatitis to be visible in another location. It is not the leakage of the blister fluid that causes other areas of the skin to be involved because there is no urushiol in the blister fluid. One should also keep in mind that there are other skin diseases that may cause blistering. It is advised to see a board certified allergist or dermatologist if you have blistering of any kind.
Identifying the differences between poison ivy, poison oak, and poison sumac is not always that easy and clinically not that important. Poison ivy and poison oak look similar and consist of compound leaves (i.e., multiple leaflets that make up 1 leaf). In the case of poison ivy and poison oak, there a 3 leaflets on each leaf. Poison ivy has 3 glossy almond-shaped leaflets with jagged edges per leaf. In the Spring, the leaves can be red or a mixture of red and green. In the Summer, the leaves are green. In the Fall, the leaves can be bright orange, yellow, or red. Poison oak has 3 fuzzy leaflets per leaf that have uneven and scalloped edges. In the different seasons, the leaves can vary from green to red. Poison oak tends to blend in around the surrounding shrubs which often makes it difficult to spot. Poison sumac has between 7 and 13 leaflets on a reddish stem and resembles a fern. The green leaflets of poison sumac are oval-shaped with a pointy top. These leaflets tend to run in pairs up the stem. It should be noted that all 3 plants may also contain berries.
Prevention of contact with poison ivy, poison oak, and poison sumac is ideally the best way to avoid the contact dermatitis that occurs with these plants. It is advisable to wear long pants, long-sleeved shirts, sleeves, gloves, and closed shoes in order to decrease the probability of contracting the rash. It is also desirable to wash one’s clothes immediately in order to remove any urushiol that may have gotten on one’s clothing from the plants.
The treatment of poison ivy, poison oak, and/or poison sumac is to wash the affected skin with a mild soap and cool water in order to try to remove the oily urushiol. Calamine lotion, zinc oxide ointment, and oral antihistamines are used often to help relieve the annoying symptoms. Occasionally oral corticosteroids and antibiotics may be necessary in more severe and recalcitrant cases and in cases of secondary infections respectively. If the rash persists and or gets worse, it is important to see a board certified allergist or dermatologist.
The board certified allergy specialists at Black & Kletz Allergy have 3 convenient locations in the Washington, DC, Northern Virginia, and Maryland metropolitan region and have been providing allergy and asthma care to this area for more than 50 years. We diagnose and treat both adults and children. Our offices are located in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. All of our offices offer on-site parking. For further convenience, our Washington, DC and McLean, VA offices are Metro accessible. In addition, our McLean, VA office location offers a complementary shuttle that runs between this office and the Spring Hill metro station on the silver line. For an appointment, please call one of our offices. Alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day. If you suffer from poison ivy, poison oak, poison sumac, contact dermatitis, hives (i.e., urticaria) hay fever (i.e., allergic rhinitis), sinus problems, asthma, or immune issues, please contact our office as it is our mission to help alleviate your undesirable symptoms, so that you can enjoy a better quality of life.
