Toxicodendron Poisoning Clinical Presentation

Updated: Jun 13, 2022
  • Author: Steven L Stephanides, MD; Chief Editor: Michael A Miller, MD  more...
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The history in cases of possible Toxicodendron toxicity should include questions about the following:

  • Known exposure to poison ivy, oak, or sumac
  • Outdoor activities in areas with Toxicodendron species within the previous 8 hours to 14 days
  • History of toxicodendron dermatitis
  • Contact with a pet that has been outside in an area with Toxicodendron species

Physical Examination

The dermatitis is highly variable and depends on the sensitivity of the patient and extent of exposure.

Mild cases

In mild cases, classic lesions on exposed skin are secondary to brushing against the plant or excoriations from scratching. Characteristics of mild classic lesions are as follows:

  • Linear
  • Erythematous, possibly edematous
  • Pruritic or mildly painful
  • May have small vesicles

Moderate-to-severe cases

Characteristics of moderate-to-severe cases are as follows:

  • Diffuse areas of erythema and edema
  • Severe pruritus and/or pain
  • Bullae (note that fluid from bullae does not contain urushiol)

Uncommonly, dermatitis from exposure to poison ivy may include black spots. The spots consist of urushiol oleoresins, which harden within minutes of exposure to air to form a black resin. [8, 9]

Erythema multiforme is an atypical presentation of toxicodendron dermatitis reported after sumac ingestion.