One last time!  My CAH daughter had chickenpox about 6 years ago - before there was a chickenpox vaccine.  My first thought would be to get the vaccine.  If for some reason you can't do that and your child is exposed, there is a medication you should have on hand that will lesson the severity if you you start it within 24 hrs of the first pox showing up.  The trouble is, I can't remember the name of it!  It is the same thing that doctors use to treat other herpes viruses (Chickenpox is a herpes virus).  I'm sure your doctor would know what this medication is.  It helps!  My daughter had it just enough to give her immunity, but not bad enough for us to get overly concerned. She started the medication hours after the first pox broke out.  Once a child gets it, coloidal oatmeal baths are great.  While we all worry about the chickenpox, another reason to get the vaccine is because having chickenpox leaves you vulnerable to shingles later in life.  Shingles is the same virus which lies dormant in your body after having chickenpox.