What is Black Spot Poison Ivy?

Discussion Poison ivy (PI, Toxicodendron radicans) is a common plant in North America that causes allergic contact dermatitis. Poison oak and sumac also cause similar problems. The rash usually appears as linear erythematous papules or vesicles occurring soon after exposure. Patients often do not identify the exposure specifically but will say they were walking/playing in gardens, fields or woods. PI can be a small plant, vine or even a shrub. The coloring changes over the growing season. Fires may also be a source as burning the plants and being in the smoke can cause extensive lesions on the body. The plant has 3 leaves and never more. The leaf stems alternate along the growing plant and are not found directly across from each other. The leaves have smooth edges and are not saw-toothed, serrated or scalloped. There also are no thorns. Several identification guides can be found here. PI has an oleoresin called urushiol which causes the main problem but it also contains allergens (pentadecylcatechols). The urushiol does not evaporate well and therefore stays on clothing, sports equipment etc.. for longer time periods. The allergens can contaminate clothing for years. These properties account for exposure at unexpected times of the year (i.e. in the winter children using a contaminated sleeping bag for an overnight party and getting the PI rash), or in unexpected places (e.g. PI rash presenting in the United Kingdom which has no PI after travel to the United States). Treatm...
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news