Smallpox is a contagious disease caused by a virus that’s no longer found in nature. For centuries, It killed millions of people around the world. But thanks to global immunization programs, the deadly infectious disease was wiped out in the late 1970s. Today, scientists keep only a small amount of the virus alive under tightly controlled conditions in the U.S. and Russia for medical research. Many adults living today likely got the vaccine as children.
The first symptoms of smallpox usually appear 10 to 14 days after you’re infected. During the incubation period of seven to 17 days, you look and feel healthy and can’t infect others. Following the incubation period, a sudden onset of flu-like signs and symptoms occurs. These include:
- Overall discomfort
- Severe fatigue
- Severe back pain
- Vomiting, possibly
A few days later, flat, red spots appear first on your face, hands, and forearms, and later on your trunk. Within a day or two, many of these lesions turn into small blisters filled with clear fluid, which then turn into pus. Scabs begin to form eight to nine days later and eventually fall off, leaving deep, pitted scars.
Lesions also develop in the mucous membranes of your nose and mouth and quickly turn into sores that break open.
Difference Between Smallpox and Chickenpox?
Smallpox and chickenpox might seem similar. They both cause rashes and blisters. They both have “pox” in their names. But other than that, they’re completely different diseases. You really don’t need to know how to tell them apart. That’s because no one in the U.S. has had smallpox for more than 65 years. But there are still important things to know about both.
- Chickenpox is still around. Smallpox is pretty much extinct.
- It is usually mild. Smallpox was often deadly.
- Kids (and some adults) need the chickenpox vaccine. Almost no one needs the smallpox vaccine.