Hi,
I posted almost exactly the same question about a month ago! My 1 year old had two blisters a few crops of other mild red spots and no itching. We did take her to the doctor who saw the blisters and said it was definitely chicken pox.
If you look through the older pages you might come across peoples answers to my question (I think I called it "is this really chicken pox?" or sth like that), but what they generally said was yes, you can have very mild attacks of chicken pox without any itching, and even with as little as one spot!
This is great for the child, but the downside is that such a mild attack might not give immunity against further attacks in the future.