Chickenpox symptoms usually last about 1 to 2 weeks. The rash appears first and new spots can keep appearing for 3 to 5 days. After that, the spots dry out, crust over, and then fall off naturally over 5 to 10 days. A person is contagious from about 2 days before the rash appears until all the spots have crusted over, which is around 5 to 7 days after the rash starts. In some cases, especially for people with weak immune systems, chickenpox can last up to 2 to 3 weeks before fully healing.