Differential Diagnosis

  • Allergic contact dermatitis
  • Hogweed dermatitis
  • Poison ivy-oak-sumac dermatitis
  • Arthropod bites or stings


This patient was diagnosed with allergic contact dermatitis due to exposure to poison ivy, poison oak, or poison sumac.


Learnings/What to Look for

  • This is a hypersensitivity reaction to an oily resin found on the leaves and in the stems and roots of plants in the Rhus genus
  • This dermatitis occurs in previously sensitized individuals, usually appearing 48 hours after antigen exposure
  • Typically presents as erythematous, linear plaques with associated vesicles and bullae
  • Pruritis is generally severe


Pearls for Urgent Care Management and Considerations for Transfer

  • Treatment includes a course of oral prednisone, starting at 1 mg/kg/day (up to 80 mg), tapering over at least 14 days (or longer, for severe reactions)
  • A 6-day tapering Dosepak should not be prescribed, as the reaction may rebound once the short course concludes


Acknowledgment: Images and presentation courtesy of VisualDx.

A 43-Year-Old Man with Pruritic, Scale Plaque and Vesicles on His Hands and Arms
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