Poison oak — a relative of poison ivy — is a plant found along the Pacific coast of North America that creates a painful rash after it comes in contact with the skin. The itchy rash, caused by the plant's urushiol oil, can take between 24 hours and a full week to appear after a person has touched the plant. While bleach should not be a first recourse for treatment because of the potential for irritation, those suffering from blisters and an itchy rash can get some measure of comfort by carefully creating a compress soaked in a diluted, half-bleach, half-water mixture.
Wash the affected area with warm water and gentle soap.
Pat the skin dry with a washcloth.
Combine equal parts water and household bleach in a small bowl or container.
Dip a clean washcloth into this mixture.
Wring out the washcloth so it is not dripping.
Drape the washcloth over the poison oak-affected skin and leave it on for 30 minutes.
Remove the washcloth and rinse the area with cold water.
Apply a layer of calamine lotion to the affected areas to soothe the skin.