Skip to main content

Poison Oak

Poison Oak is a skin rash caused by sensitivity to the irritating oil of the poison oak plant.


Itchy pimples and blisters may begin at any time up to the third or fourth day after exposure, and may continue to increase in number for a week or so. The lesions become less itchy as they dry and subside within a few days after appearance.

  • Causes of Continual or Recurrent Episodes
  • Repeated contact with plant in an unsuspected location
  • Contact with fur of cat or dog who roams the hills
  • Contact with furniture that has been rubbed with poison oak from your clothes when you first returned home after exposure, or from contamination by cat or dog

New areas may break out for up to a week after exposure, but you do not spread it from one area to another by your hands or direct contact. The serum from the blisters will not spread it to normal skin.

Spreading to Others

Serum from your blisters will not spread the rash to another person, but contact with you or your clothes which are contaminated with the plant oil will cause rash in others.


Treatment is directed at decreasing the itching, since scratching increases the involved areas and increases the risk of infection.


Wash skin with tepid water and strong laundry soap as soon as possible after exposure. Have all clothes worn at time of exposure washed or cleaned before wearing again.

Please call Student Health at 858-534-3300 if the rash is worsening, not resolving, or changing.