If your child has a rash due to coming into contact with poison ivy, it is important to first wash the affected area with cold water and make sure to remove any plant debris. To help relieve symptoms, you can use cold water compresses for 15 to 30 minutes several times a day. You may also consider using colloidal oatmeal cream or a mixture of colloidal oatmeal and baking soda in the bath. Avoid hot water during baths or showers as it may further irritate the skin. If the reaction is severe, you can consult with a pharmacist about using a cortisone cream. It is important to ensure your child's comfort and keep the affected area clean to promote healing.