Suggest Remedy For Skin Rash Caused By A Poison Oak

my son was chopping wood that had poison oak on it. The next day, he got a rash on his face that at that time was a little raised. Now, 5 days later, he has petechiae on his face and eyelids. The rash itched for a couple days, but not anymore so I don't beleive the petechiae is from scratching. The rash in some areas appears to be "scratches". He does not feel ill or has not ran any fever. Should I be concerned?