Poison Ivy, Poison Oak & Poison Sumac Symptoms

Direct contact with poisonous plant for the first time causes sensitivity. In most cases, this exposure does not produce a reaction. Sensitivity to poison ivy varies from person to person. In some people, subsequent exposure results in a skin rash that develops within 12–48 hours.

Symptoms can be mild, moderate, or severe and include itching, redness (erythema), and blisters. The rash often is linear (i.e., appears in a line where the leaves of the plant have touched the skin). Blisters may ooze clear fluid and usually begin to crust over in a few days. In most cases, rashes caused by poison ivy, poison oak, and poison sumac heal completely in a week or two.

Poison ivy does not spread by touching the rash. In many cases, symptoms develop gradually on areas of the body that absorb urushiol more slowly. Rashes rarely occur on the soles of the feet or the palms of the hands because the skin is thicker in these areas.

In some cases, poison ivy, poison oak, and poison sumac can result in complications. Scratching may prolong the rash, can cause a secondary bacterial infection, and increases the risk for scarring. Complications also can occur when the toxin (urushiol) is inhaled into the nose and throat.

Other complications may indicate a severe allergy and include the following:

  • Difficulty breathing or speaking (e.g., hoarseness)
  • Dizziness or lightheadedness
  • Swelling around the nose and mouth
  • Tightness in the chest
  • Widespread redness or swelling

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 23 Aug 2007

Last Modified: 01 Oct 2015