What is chickenpox?
Chickenpox, also known as varicella, is a highly contagious disease caused by the initial infection with varicella zoster virus (VZV). The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over. It usually starts on the chest, back, and face. It then spreads to the rest of the body. Other symptoms may include fever, tiredness, and headaches. Symptoms usually last five to seven days. Complications may occasionally include pneumonia, inflammation of the brain, and bacterial skin infections. The disease is often more severe in adults than in children. Symptoms begin 10 to 21 days after exposure to the virus.
Chickenpox is an airborne disease which spreads easily through the coughs and sneezes of an infected person. It may be spread from one to two days before the rash appears until all lesions have crusted over. It may also spread through contact with the blisters. Those with shingles may spread chickenpox to those who are not immune through contact with the blisters. The disease can usually be diagnosed based on the presenting symptom; however, in unusual cases it may be confirmed by polymerase chain reaction (PCR) testing of the blister fluid or scabs. Testing for antibodies may be done to determine if a person is or is not immune. People usually only get chickenpox once. Although reinfections by the virus occur, these reinfections usually do not cause any symptoms.
Symptoms
Before the rash appears, there will be:
- a general feeling of being unwell (malaise)
- fever, which is usually worse in adults than children
- aching muscles
- loss of appetite
- in some cases, a feeling of nausea
After the rash appears, there will be:
- Rash: Severity varies from a few spots to a rash that covers the whole body.
- Spots: The spots develop in clusters and generally appear on the face, limbs, chest, and stomach. They tend to be small, red, and itchy.
- Blisters: Blisters can develop on the top of the spots. These can become very itchy.
- Clouding: Within about 48 hours, the blisters cloud over and start drying out. A crust develops.
- Healing: Within about 10 days, the crusts fall off on their own.
During the whole cycle, new waves of spots can appear – in such cases, the patient might have different clusters of spots at varying stages of itchiness, dryness, and crustiness.
Other symptoms
A few people have more severe symptoms.
If the following occur, a doctor should be contacted:
- the skin around the spots or blisters becomes painful and red
- there are breathing difficulties
Most healthy individuals make a full recovery, as with a cold or flu, by resting and drinking plenty of fluids.
What causes chickenpox?
Varicella-zoster virus (VZV) causes the chickenpox infection. Most cases occur through contact with an infected person. The virus is contagious to those around you for one to two days before your blisters appear. VZV remains contagious until all blisters have crusted over. The virus can spread through:
- saliva
- coughing
- sneezing
- contact with fluid from the blisters
Who is at risk of developing the chicken pox?
Exposure to the virus through previous active infection or vaccination reduces risk. Immunity from the virus can be passed on from a mother to her newborn. Immunity lasts about three months from birth.
Anyone who has not been exposed may contract the virus. Risk increases under any of these conditions:
- You have had recent contact with an infected person.
- You are under 12 years of age.
- You are an adult living with children.
- You have spent time in a school or child care facility.
- Your immune system is compromised due to illness or medications.
Stages
Chickenpox develops in stages.
Transmission
Chickenpox, colds, and flu spread in a similar way. People can be infected by touching the blisters directly or from breathing in particles of the virus from the blisters or from the air around someone who is infected.
Chickenpox is mostly transmitted by:
- direct contact with the blisters of someone who has the varicella zoster virus
- breathing in the virus particles from someone’s blisters
- breathing in small particles from the mouth of someone talking or coughing
Varicella has an incubation period of between 10 and 21 days. In other words, the rash will appear from 10 to 21 days after exposure to the virus.
The rash
An infected person is contagious about 2 days before the rash appears. The rash can involve 250 to 500 itchy blisters.
Chickenpox continues to be contagious for another 5 to 7 days, or until all of the blisters have become scabs.
When all the lesions have crusted over, those infected can no longer pass it on to others, but individuals with weakened immune systems may be contagious for longer.
How is chickenpox diagnosed?
You should always call your doctor any time you develop an unexplained rash, especially if it’s accompanied by cold symptoms or fever. One of several viruses or infections could be affecting you. Tell your doctor right away if you are pregnant and have been exposed to chickenpox.
You doctor may be able to diagnose chickenpox based on a physical exam of blisters on you or your child’s body. Or, lab tests can confirm the cause of the blisters.
How Is It Spread?
Very easily. You can get the virus by breathing in particles that come from chickenpox blisters or by touching something on which the particles landed.
Chickenpox is most contagious from 1 to 2 days before the rash appears until all the blisters are dried and crusted.
The best way to prevent the spread of the virus is to get the varicella vaccine. Children who’ve never had chickenpox should get two doses of the vaccine — the first at 12 to 15 months of age, and the second between ages 4 and 6. People over age 13 who’ve never been vaccinated should get two doses of the vaccine at least 28 days apart.
Treatment
Chickenpox generally resolves within a week or two without treatment. There is no cure, but a vaccine can prevent it.
A doctor may prescribeTrusted Source medication or advise on how to reduce symptoms of itchiness and discomfort, and also on how to prevent the infection from spreading to other people.
Pain or fever: Tylenol (acetaminophen), which is available to purchase online, may help with symptoms of high temperature and pain. It is important to follow the instructions provided by the manufacturer. Aspirin containing products should NOT be used for chickenpox as this can lead to complications. Acetaminophen (Tylenol) can be used at any time during pregnancy.
Avoiding dehydration: It is important to drink plenty of fluids, preferably water, to prevent dehydration. Some doctors recommend sugar-free popsicles or Pedialyte for children who are not drinking enough.
Mouth soreness: Sugar-free popsicles help ease symptoms of soreness if there are spots in the mouth. Salty or spicy foods should be avoided. If chewing is painful, soup might be a good option, but it should not be too hot.
Itchiness: ltchiness can become severe, but it is important to minimize scratching to reduce the risk of scarring.
The following may help prevent scratching:
- keeping fingernails clean and as short as possible
- placing mittens or even socks over a child’s hands when they go to sleep, so that any attempt at scratching during the night does not cut the skin
- applying calamine lotion or having an oatmeal bath to reduce itching
- wearing loose clothing
Antiviral medicationmay be prescribed during pregnancy, for adults who get an early diagnosis, in newborns, and for those with a weakened immune system. Acyclovir is one example.
This works best if it is given within 24 hours of developing symptoms. Acyclovir reduces the severity of symptoms but does not cure the disease.
What are possible complications of chickenpox?
Call your doctor right away if:
- The rash spreads to your eyes.
- The rash is very red, tender, and warm (signs of a secondary bacterial infection).
- The rash is accompanied by dizziness or shortness of breath.
When complications occur, they most often affect:
- infants
- older adults
- people with weak immune systems
- pregnant women
These groups may also contract VZV pneumonia or bacterial infections of the skin, joints, or bones.
Women exposed during pregnancy may bear children with birth defects, including:
- poor growth
- small head size
- eye problems
- intellectual disabilities
Risk factors
Your risk of becoming infected with the varicella-zoster virus that causes chickenpox is higher if you haven’t already had chickenpox or if you haven’t had the chickenpox vaccine. It’s especially important for people who work in child care or school settings to be vaccinated.
Most people who have had chickenpox or have been vaccinated against chickenpox are immune to chickenpox. If you’ve been vaccinated and still get chickenpox, symptoms are often milder, with fewer blisters and mild or no fever. A few people can get chickenpox more than once, but this is rare.
Prevention
A vaccine is available for varicella. For children, 2 doses of the varicella vaccine are given, one at 12 to 15 months and one at age 4 to 6 years. These are 90 percent effective at preventing chickenpox.
In the United States, the chickenpox vaccine is routinely given to children.
Chickenpox and pregnancy
During pregnancy, there is a slightly higher risk of developing pneumonia with chickenpox.
There is also a danger of passing the infection on to the fetus.
If infection occurs during the first 20 weeks of pregnancy, there is a higher risk of fetal varicella syndromeTrusted Source, which can lead to scarring, eye problems, brain drainage, and shortened arms or legs.
If the infection happens later in pregnancy, the varicella may be transmitted directly to the fetus and the baby can be born with varicella.
If you become exposed to varicella during pregnancy, whether chickenpox or shingles, it is important to talk to a doctor right away.
Shingles
Chickenpox and shingles are caused by the same virus. Shingles occurs when the varicella zoster virus from a previous case of chicken pox becomes active again.
Complications of shingles can include:
- postherpetic neuralgia, with pain from shingles lasting long after the blisters have gone
- vision loss if shingles cause eye infections
- neurological problems due to inflammation in the brain
- skin infections, especially if blisters are not treated correctly
You cannot catch shingles from another person, but a person who has never had chickenpox or was never vaccinated can catch chickenpox from someone with shingles. However, you cannot get shingles from somebody with chickenpox.
What is the long-term outlook?
The body can resolve most cases of chickenpox on its own. People usually return to normal activities within one to two weeks of diagnosis.
Once chickenpox heals, most people become immune to the virus. It won’t be reactivated because VZV typically stays dormant in the body of a healthy person. In rare cases, it may re-emerge to cause another episode of chickenpox.
It is more common for shingles, a separate disorder also triggered by VZV, to occur later during adulthood. If a person’s immune system is temporarily weakened, VZV may reactivate in the form of shingles. This usually occurs due to advanced age or having a debilitating illness.
Frequently Asked Questions
What is Chickenpox?
Chickenpox is a very contagious disease caused by the varicella virus. The virus usually infects children, however adults who were not infected as children can also become infected if exposed to the virus. Chickenpox is most common in late winter to early spring.
What causes chickenpox?
Chickenpox is caused by a virus, the varicella-zoster virus.
How long does it take to show signs of chickenpox after being exposed?
It takes from 10 to 21 days to develop symptoms after being exposed to a person infected with chickenpox. The usual time period is 14–16 days.
My child was vaccinated years ago and this year he/she developed a mild case of chickenpox. Why did this happen?
No vaccine is 100% effective. Breakthrough disease may be due to a number of different factors. One reason is that some people do not develop enough protection to completely prevent them from developing chickenpox. When they come into contact with a case of chickenpox, they may develop breakthrough
disease.
What are the symptoms of chickenpox?
The most common symptoms of chickenpox are rash, fever, coughing, fussiness, headache, and loss of appetite. The rash usually develops on the scalp and body,
and then spreads to the face, arms, and legs. The rash usually forms 200–500 itchy blisters in several successive crops. The illness lasts about 5–10 days.
How serious is chickenpox?
Many cases of chickenpox are mild, but deaths from this disease can occur. Before vaccine became available, about 100 people died every year in the United
States from chickenpox. Most of these people were previously healthy. Chickenpox also accounted for about 11,000 hospitalizations each year. Even children with average cases of chickenpox are uncomfortable and need to be kept out of daycare or school for a week or more.
What are possible complications from chickenpox?
The most common complication is bacterial infection of the skin or other parts of the body including the bones, lungs, joints, and blood. The virus can also lead to pneumonia or infection of the brain. These complications are rare but serious. Complications are more common in infants, adults, and people with
weakened immune systems.
How do I know if my child has chickenpox?
Usually chickenpox can be diagnosed by disease history and appearance alone. Adults who need to know if they’ve had chickenpox in the past can have this determined by a laboratory test. Chickenpox is much less common now than it was before a vaccine became available, so parents, doctors, and nurses are less familiar with it. It may be necessary to perform laboratory testing for children to confirm chickenpox.
How long is a person with chickenpox contagious?
Patients with chickenpox are contagious for 1–2 days before the rash appears and continue to be contagious through the first 4–5 days or until all the blisters
are crusted over.
Is there a treatment for chickenpox?
Most cases of chickenpox in otherwise healthy children are treated with bed rest, fluids, and control of fever. Children with chickenpox should NOT receive aspirin because of possible subsequent risk of Reye’s syndrome. Acetaminophen may be given for fever control. Chickenpox may be treated with an antiviral drug in serious cases, depending on the patient’s age and health, the extent of the infection, and the timing of the treatment.