Poison ivy, poison oak and poison sumac cause an itchy, blistering rash on the skin due to the oil found in the plants. The oil is called urushiol. After coming in contact with the plant, reaction often begins after 12-72 hours. Touching the plant, touching something that has come in contact with the plant and being near to the plant could transfer the oil to the skin.
Contrary to popular thought, the rash is not contagious and does not spread. It might appear to have spread, but this is a delayed reaction to the plant oil.
The rash will go away in a few weeks. Cool showers, an oatmeal bath, applying calamine lotion or hydrocortisone may all provide relief. Chelsea Skin & Laser will help identify the type of dermatitis you have and advise a care plan accordingly. If you have a serious reaction, especially swelling of the eyes or face, trouble breathing or swallowing, go to an emergency room to seek immediate care.