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Phytodermatitis Slides 21 through 25

Reprinted with permission from the American Academy of Dermatology. All rights reserved. Please note that the slides are very large JPEG files that will take up to 6.5 minutes to view or download using a 28.8 kbps modem.

Allergic Contact Dermatitis

Allergic contact dermatitis requires previous sensitization to low molecular weight compounds in a plant. Not everyone develops an allergic reaction to these compounds. The most common plant causing this reaction is poison oak or ivy. The large family of plants, Compositae, contain chemicals called sesquiterpene lactones, which are sensitizers and irritants. Most of these rashes are chronic, eczematous rashes as compared to the severe blisters that develop from contact with the poison oak or ivy plants. Allergic contact dermatitis is the least common type of plant reaction except for problems with poison oak or ivy.

Slide 21

The poison ivy plant (Toxicodendron radicans) has leaves grouped in three and can grow vine‑like up the trunks of trees. The leaves of the Western shrub‑like poison oak plant (Toxicodendron diversibolum) are also grouped in three but are shorter than poison ivy and are slightly lobed on the edge resembling oak‑shaped leaves.

Poison ivy (Toxicodendron radicans)

Return to Phytodermatitis Index or Dermatitis Educational Material.

Slide 22

The ginkyo tree (Ginkyo biloba) has distinctive fan-shaped leaves. The allergen (ginkgolic acid) is similar to urushiol oil.

Leaf of the Ginkyo tree (Ginkyo biloba)

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Slide 23

The ginkyo tree (Ginkyo biloba) allergen (ginkgolic acid) is present in the ovule of the female tree.

Ovule of the female Ginkyo tree

Return to Phytodermatitis Index or Dermatitis Educational Material.

Slide 24

The artichoke (Cynara scolymus) has an edible flowering head. Allergic reactions to the sesquiterpene lactone compound in the stems and roots can be seen in pickers, florists and produce workers in groceries.

Artichoke (Cynara scolymus)

Return to Phytodermatitis Index or Dermatitis Educational Material.

Slide 25

Yarrow (Achilles millefolium).

Yarrow (Achilles millefolium)

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