Smallpox and chickenpox both cause blisters that damage the skin. However, the rash in chickenpox appears in clusters on the face, abdomen, back, and scattered on the arms. Smallpox is concentrated in the arms and legs.

Smallpox is a common acute infectious disease that can occur at any age and is most common in children. People carry the smallpox virus when they talk, sneeze, or cough.

Smallpox is a disease caused by the Variola virus. It is a highly fatal disease characterized by severe systemic symptoms and a characteristic pustular rash. Treatment can be supportive and antiviral. However, vaccination is recommended to prevent this disease.