Poison Ivy:
Contact
Dermatitis caused by a member of the Toxicodendron Genus with wide
geographic distribution, is an allergic reaction to a chemical mixture
named Urushiol. Initial contact causes sensitization but no symptoms.
Subsequent contacts lead to production of toxic substances by the body
to destroy the cells that bind Urushiol. This process produces
blistering, swelling, redness and itching. Decontamination consists of
rinsing affected skin with soap and water within 5-30 minutes of
exposure. An Over the Counter product called Zanfel can be applied as
late as several days after exposure to reduce the rash. Oral prednisone
for 14-21 days is also effective.