From Kids Health “Chickenpox causes a red, itchy rash on the skin that usually appears first on the abdomen or back and face, and then spreads to almost everywhere else on the body, including the scalp, mouth, nose, ears, and genitals. The rash begins as multiple small, red bumps that look like pimples or insect bites. They develop into thin-walled blisters filled with clear fluid, which becomes cloudy. The blister wall breaks, leaving open sores, which finally crust over to become dry, brown scabs. Chickenpox blisters are usually less than a quarter of an inch wide, have a reddish base, and appear in bouts over 2 to 4 days. ” There is treatment information there too.