POISON IVY

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POISON IVY
Clark B. Montgomery Beltrami County Extension
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Leaves Of Three . . .-Let It Be
Leaves of Four . . . . . . -Buy a Lottery
Ticket
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Three To Leave
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North American Toxicodendron
Poison Ivy T. rydebergii/radicans
Poison Oak T. pubescens/diversilobum
Poison Sumac T. vernix
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POISON IVY
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Physiological Features
Petiolule
Drupe
Petiole
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Look Alikes?
English Ivy
Virginia Creeper
Boston Ivy
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Poison Oak
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Poison Sumac
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Urushiols(yoo-ROO-she-ol)
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Acute Contact Dermatitis
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Urushiol Plants WorldwideAnacardiaceae
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Urushiol Oil Facts

• one nanogram (1/1,000,000,000 g.) can trigger a
  rash in highly sensitive individuals
• 100 nanograms (1/10,000,000 g.) is required for a
  rash in most people
• active urushiol can persist for 5 years on most
  surfaces
• specimens containing urushiol several centuries
  old have caused dermatitis in some individuals
• human sensitivity can occur at any time

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Poison Ivy Facts

• poison ivy is not contagious nor can it be spread
  to other parts of the body by rubbing or
  scratching
• breaking rash blisters does not release urushiol
  and cause the inflammation to spread
• direct contact with urushiol is required for rash
  development
• urushiols can be present on pond water
• approximately 15 of the population is immune

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Poison Ivy Myths

• gain immunity by eating honey made from poison
  ivy nectar and/or pollen
• gain immunity by drinking milk from goats grazing
  poison ivy
• washing exposed area with yellow soap will
  prevent a rash
• scrubbing the skin with harsh chemical (gasoline,
  carbolic acid, ammonia, etc.) will cure a rash
• eating poison ivy leaves can make you immune

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Prevention

• learn to identify and avoid ALL possible contact
  with urushiol containing plants
• immediately upon contact, wash skin area with
  soap and cool water or swab with alcohol
• avoid inhaling smoke from forest fires or burning
  yard debris
• avoid handling firewood, tools or pets that may
  have come in contact with urushiol
• clothing and/or barrier creams (Ivy Shield,
  Hydrophil, etc.)
• medical desensitization?

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Controlling Poison Ivy Plants

• Triclopyr
• selective herbicide - wont damage grass
• apply at bloom or later
• repeat applications may be required

• Glyphosate
• non-selective herbicide
• apply at bloom or later
• repeat application may be required