Wash the area with soap, water, and baking soda (sodium bicarbonate).
Work Step by Step
The component inpPoison ivy, alkyl substituted catecholamines, are non-polar and are not soluble in water. Soap will help dissolve the non-polar substance. Further, the pKa of the substance is 8, so an alkaline medium will increase the dissociation and so solubility. For this, sodium carbonate can be added.