Chickenpox is an infectious disease that results in blister-like rashes, itching, fever, and tiredness. Early symptoms of the disease may include one to two days of low-grade fever and tiredness. However, these early symptoms of chickenpox do not always occur before the chickenpox rash develops. The chickenpox rash first begins to appear on the trunk, face, and scalp -- and can eventually spread over the entire body. This rash can appear in three or move successive waves. Chickenpox is caused by the varicella-zoster virus. In most cases, the condition can be treated at home through close monitoring of the symptoms.