K.T.
V.,
My son had it when he was 3. The doctor said it comes on like any other virus, but affects kids differently. It was 6 years ago, but what I remember, it lasted maybe a week at the most. He had a raised rash on his face and chest, and his wrists were swollen so that he couldn't hold his sippy cup. He never had blisters at all. It seemed bad at the time and I remember having him sleep with me so I could watch him. I hope this helps and that all goes well.
K.