The best treatment is prevention: know what it looks like and teach the kids and avoid it.
Know where you are going. Open spaces have poison oak, forested areas have poison oak. If you have active, unstoppable explorers, plan ahead and before heading out apply one of the clay-based products (one brand is Ivy Block) that make a barrier between skin and the irritating oils.
If balls or toys go into the brush, leave them or retrieve them with something disposable like a paper towel or anything that can easily be washed or cleaned. Dogs, clothing and sports equipment can be coated by the colorless oil and can spread poison oak to other areas and people.
If you know the kids might have been exposed to poison oak, clean up afterwards with a product that gets the oil off the skin (one is Technu). The average person has 1 to 4 hours to get the oil off the skin, but don’t wait! While the poison oak rash develops over 1-2 days for people who have had it before, sensitive people can develop a severe rash within hours. Sometimes the rash can even take 10-14 days to develop, especially if this is the first time the person is exposed.
If the poison oak rash develops, keep your child comfortable with cool compresses, oatmeal baths, antihistamines like diphenhydramine and hydrocortisone cream. Avoid scratching because this can lead to a separate skin infection. The poison oak rash can take 2-3 weeks to clear. Call or see your pediatrician for questions or concerns.