It is a virus that infects the body, causing the typical illness.
Most people know about the rash, but chicken pox starts out just like a common cold.
Runny nose, sneezing, cough and fever are typical first symptoms of chicken pox. About three to five days later the rash shows up, looking like dots ranging from the size of an eraser head to about the size of a dime. Within each of these dots is a fluid-filled vesicle that may pop over the course of the following days. The lesions may be painful or itchy, or not be bothersome at all. They may be found anywhere on the skin, in the mouth, and within the vaginal area and even unseen within the penis.