for Children and Adults
Sherry Guralnick Cohen
Board Certified Registered Nurse Practitioner

© 2001-2011 Dermatlas

Poison Ivy

The rash of poison ivy appears 12-48 hours after contact with the plant by sensitive individuals.  It forms  a linear pattern at the sites of direct contact.   Once your skin and clothes have been washed, the rash will not spread.   However, there may be a delay in appearance of the rash at different sites on the body after the initial exposure.  Symptoms include itching, reddness, swelling, and blisters which may later form crust.


Poison Ivy is caused by a delayed hypersensitivity reaction from contact with  the urushiol oil found in the sap of the leaves, stems, and roots of the plant in sensitized individuals.   The clue to recognizing the plant is "leaves be three, let it be"     Poison sumac and Poison oak which grow in different parts of the country cause a similar reaction.   Learn to recognize these plants so you can avoid them.