Dr. Cole is board certified in dermatology. He obtained his BA degree in bacteriology, his MA degree in microbiology, and his MD at the University of California, Los Angeles. He trained in dermatology at the University of Oregon, where he completed his residency.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Myth #1: These plants are poisonous. Truth:
Poison ivy, poison oak, and
poison sumac are all members of
the Toxicodendron genus. All members of this group produce chemicals in their
plant juices to which most human beings are able to develop a brisk
response. The first time one comes into contact with these chemicals there is
generally no reaction but the immune system is stimulated to develop the
capacity to recognize the molecule the next time a contact occurs.
Myth #2: One must
come into direct contact with the plant to develop a rash. Truth: Generally
direct contact with plant juice is required. Occasionally reactions can occur if
this juice is transferred indirectly onto the skin of a sensitive individual (for example, from the fur of a pet or clothing that has been contaminated with
the plant oils). Sometimes blowing wind, especially soon after a brushfire, can
contain enough chemical to cause a
rash in very sensitive people.
Myth #3: The
appearance of the rash is characteristic for Toxicodendron dermatitis. Truth:
There is nothing specific about the appearance of the eruption. Any other plant
allergic contact dermatitis could potentially appear identical. The rash appears
as red, itchy bumps and small blisters often distributed in a linear fashion on
exposed surfaces. When the blisters rupture, there can be weeping and oozing.
Myth #4: The weeping blister fluid can spread the rash to someone else. Truth: The only
way to spread this rash from one person to another is by the transfer of the
plant juice. The blister fluid generally does not contain the allergenic
chemical so this is not likely to ever occur.
Myth #5: Individuals allergic to Toxicodendron can react to other members of closely related botanical groups. Truth: This is true. The allergen present in this plant group is structurally
similar enough to react to plant juices from other members of the family Anacardiaceae, like cashew nut oil, mango rind, and certain Chinese lacquers.
Myth #6: Allergic individuals can be desensitized by eating the leaves of the plant. Truth: It is very difficult to desensitize an allergic individual to this family
Myth #7: Once the eruption occurs,
there are a variety of treatments that easily suppress the reaction and can be
performed without visiting your physician. They vary from applying human urine
to the site of the eruption to drenching the skin in gasoline. Truth: For mild
local reactions, it is generally necessary to apply potent topical steroids to
the site for two to three weeks. For more severe reactions, it is often necessary to take
oral cortisone (prednisone) in the appropriate dosage for two to three weeks.
Myth #8: There are barrier creams which can be applied to the skin prior
to potential exposures which can prevent the rash. Truth: In the April 2001
issue of the Skin Therapy Letter, two products are mentioned that appear to have
significant potential to act as a barrier to the chemical allergen: quaternium-18 bentonite cream (Ivy Block) and Stokogard cream.
Lee, Nancy P., and Edgar R. Arriola. "Poison Ivy, Oak, and Sumac Dermatitis."
Western Journal of Medicine 171 Nov./Dec. 1999: 354-355.