Chickenpox

Chickenpox is a sickness that spreads easily.

It can spread through coughs and sneezes. You can also get it by touching itchy spots.

It starts with red dots on the face and body. These dots turn into itchy bumps and blisters. Soon, they turn into scabs.

It can make you feel very tired. You might also have a fever or a headache. Most people get it only once.

Some people get a shot to stay safe. This shot helps keep you from getting very sick. It is a good way to stay healthy.

Chickenpox is a sickness caused by a virus. This virus is called varicella zoster.

It spreads very easily from person to person. You can catch it through coughs or sneezes. It also spreads by touching the blisters on the skin. A person can spread the virus even before they see a rash. They stay contagious until all the spots turn into dry scabs.

The sickness usually starts with red dots. These dots turn into itchy bumps and small blisters. These blisters can appear on the face, chest, or back. They may also show up in the mouth. After a few days, the blisters turn into scabs. Most people feel tired or have a fever too.

Most people only get chickenpox once. The virus stays in the body for a long time. Many years later, it can wake up again. This causes a different sickness called shingles.

We can use a vaccine to stay safe. A vaccine is a shot that helps the body fight the virus. In the United States, the number of cases has dropped by nearly 90 percent since the vaccine began. This helps keep people from getting very sick.

Chickenpox is a highly contagious sickness. It is caused by the varicella zoster virus. This virus belongs to a group called herpesviruses.

Most people only get chickenpox one time. The disease causes a very itchy skin rash. This rash usually starts on the face, chest, or back. It then spreads to the rest of the body. While it is usually mild for children, it can be more severe for adults. Some people may even face serious problems like pneumonia or brain inflammation.

The way the sickness works follows a specific path. First, a person breathes in the virus through coughs or sneezes. This is called airborne transmission. The virus stays hidden for 10 to 21 days. This waiting time is called the incubation period. Then, the rash appears as small red dots. These dots turn into bumps and blisters over 10 to 12 hours. Eventually, the blisters turn into dry scabs. A person can spread the virus even before the rash shows up. They stay contagious until every single blister has crusted over.

People have known about this sickness for a long time. The name "chickenpox" was first written down in 1658. Some think it was named after the way chicken beaks peck. Others think it was named because the sickness is mild. Scientists did not separate chickenpox from smallpox until the late 19th century. In 1888, experts found that it was connected to shingles. In the early 1970s, Michiaki Takahashi and his team in Japan developed a vaccine. Later, in 1995, a team at Merck helped bring the vaccine to the United States.

There are many important numbers to know about this virus. In 2013, there were 140 million cases of chickenpox and shingles worldwide. In 2015, there were 6,400 deaths globally from the disease. This was lower than the 8,900 deaths recorded in 1990. In the United States, the vaccine has helped decrease infections by nearly 90 percent. The vaccine protects about 70 to 90 percent of people. Death occurs in about 1 out of every 60,000 cases. These numbers show how much vaccines can help the world.

You might know someone who has had itchy spots or a fever. Chickenpox is similar to how a cold spreads through a room. It is also linked to a later sickness called shingles. After the first infection, the virus stays dormant in your nerve tissues. It can sleep there for about 50 years. If the virus wakes up, it causes shingles instead of chickenpox. To help with the itch, people sometimes use calamine lotion. Keeping fingernails short can also help prevent injury from scratching.

Chickenpox is a highly contagious disease caused by the varicella zoster virus (VZV). This virus is a member of the herpesvirus family.

The illness is characterized by an itchy skin rash that forms small blisters. These blisters eventually scab over as the body heals. While many people experience chickenpox as a mild childhood illness, it can be much more severe in adults. It is an airborne disease, meaning it spreads easily through human-to-human transmission. People often catch it through the coughs and sneezes of someone who is already infected.

The process of infection follows a very specific timeline. After a person is exposed to the virus, there is an incubation period of 10 to 21 days. During this time, the virus is active in the body, but no symptoms are visible. The disease often begins with prodromal symptoms, which are early warning signs. In adolescents and adults, these may include nausea, loss of appetite, aching muscles, and headaches. In children, these early signs are often absent. Instead, the first sign is usually the appearance of the rash or spots inside the mouth.

The physical rash develops in distinct stages. It typically begins as small red dots on the face, scalp, torso, and limbs. Over a period of 10 to 12 hours, these dots progress into small bumps, blisters, and pustules. These blisters often undergo umbilication, which means they develop a central indentation. Eventually, the blisters dry out and form scabs or crusts. This external rash is called an exanthem. Sometimes, an internal rash called an enanthem appears in the oral cavity or tonsil areas. This internal rash can appear one to three days before the external rash or at the same time.

Understanding when a person is contagious is vital for preventing spread. A person can spread the virus one to two days before the rash even appears. This happens because watery nasal discharge containing the live virus often precedes the rash. Contagiousness continues until all the lesions have become dry crusts. This process usually takes four or five days. People can also spread the virus through direct contact with the fluid in the blisters. Those suffering from shingles can also spread the virus to people who are not immune by contact with their blisters.

History shows how our understanding of this virus has evolved. The first documented use of the term "chickenpox" dates back to 1658. People have suggested many reasons for this name. Some believed the rash looked like the pecks from a chicken's beak. Others thought the name reflected how mild the infection felt. Scientists did not separate chickenpox from smallpox until the late 19th century. In 1888, researchers determined that chickenpox was connected to shingles. In the early 1970s, Michiaki Takahashi and his colleagues in Japan developed a live attenuated varicella vaccine using the Oka strain. This was later licensed in the United States in 1995 by Maurice Hilleman's team at Merck.

The impact of the disease is reflected in significant global statistics. In 2013, there were 140 million cases of chickenpox and shingles worldwide. In 1990, there were 8,900 deaths globally from the disease, but this number fell to 6,400 in 2015. Death occurs in approximately 1 per 60,000 cases. In the United States, the introduction of the vaccine has caused the number of infections to decrease by nearly 90 percent. The vaccine is highly effective, protecting about 70 to 90 percent of people from the disease. It provides an even greater benefit in preventing severe cases.

Chickenpox is also closely linked to a later condition called shingles, or herpes zoster. After the initial infection, the VZV virus remains latent, or dormant, in the sensory nerve cells. It can stay in the body for about 50 years. If the virus reactivates, it causes shingles rather than chickenpox. This reactivation can happen at any age, but it is most common in adults over age 60. Shingles affects about one in five adults who had chickenpox as children. The virus can also affect the arteries in the head and neck, which can lead to a stroke. This connection shows how a single virus can impact the body in many different ways over a lifetime.