Chickenpox is a mild and common childhood illness that most children catch at some point.
It causes a rash of red, itchy spots that turn into fluid-filled blisters. They then crust over to form scabs, which eventually drop off.
Some children have only a few spots, but other children can have spots that cover their entire body. These are most likely to appear on the face, ears and scalp, under the arms, on the chest and belly, and on the arms and legs.
Read more about the symptoms of chickenpox and watch a slideshow of common childhood conditions to help you recognise if your child has it.
Chickenpox (known medically as varicella) is caused by a virus called the varicella-zoster virus. It's spread quickly and easily from someone who is infected.
Read more about the causes of chickenpox.
Chickenpox is most common in children under the age of 10. In fact, chickenpox is so common in childhood that over 90% of adults are immune to the condition because they've had it before.
Children usually catch chickenpox in winter and spring, particularly between March and May.
Symptoms
Chickenpox often starts with a fever, headache, sore throat, or stomachache. These symptoms may last for a few days, with the fever in the 101°-102°F (38.3°-38.8°C) range.
Chickenpox causes a red, itchy skin rash that usually appears first on the abdomen or back and face, and then spreads to almost everywhere else on the body, including the scalp, mouth, arms, legs, and genitals.
The rash begins as multiple small red bumps that look like pimples or insect bites, usually less than a quarter of an inch wide. They appear in crops over 2 to 4 days and develop into thin-walled blisters filled with fluid. The blister walls break, leaving open sores, which finally crust over to become dry, brown scabs. The rash is very itchy, and cool baths or calamine lotion may help to manage the itching.
A hallmark of chickenpox is that all stages (red bumps, blisters, and scabs) can appear on the body at the same time. The rash may be more extensive or severe in kids who have skin disorders like eczema or weak immune systems. Young kids tend to have a mild illness with fewer blisters than older children or adults.
In rare cases, serious bacterial infections involving the skin, lungs, bones, joints, and the brain can happen.
Chickenpox (varicella) is a contagious illness that causes an itchy rash and red spots or blisters (pox) all over the body. Chickenpox can cause problems for pregnant women, newborns, teens and adults, and people who have immune system problems that make it hard for the body to fight infection.
Chickenpox usually isn't a serious health problem in healthy children. But a child with chickenpox needs to stay home from school. And you may need to miss work in order to care for your child.
After you have had chickenpox, you aren't likely to get it again. But the virus stays in your body long after you get over the illness. If the virus becomes active again, it can cause a painful viral infection called shingles.
Chickenpox is caused by the varicella-zoster virus. It can spread easily. You can get it from an infected person who sneezes, coughs, or shares food or drinks. You can also get it if you touch the fluid from a chickenpox blister.
A person who has chickenpox can spread the virus even before he or she has any symptoms. Chickenpox is most easily spread from 2 to 3 days before the rash appears until all the blisters have crusted over.
You are at risk for chickenpox if you have never had the illness and haven't had the chickenpox vaccine. If someone you live with gets chickenpox, your risk is even higher because of the close contact.
The first symptoms of chickenpox usually develop about 14 to 16 days after contact with a person infected with the virus. Most people feel sick and have a fever, a decreased appetite, a headache, a cough, and a sore throat. The itchy chickenpox rash camera.gif usually appears about 1 or 2 days after the first symptoms start.
After a chickenpox red spot appears, it usually takes about 1 or 2 days for the spot to go through all its stages. This includes blistering, bursting, drying, and crusting over. New red spots will appear every day for up to 5 to 7 days.
It usually takes about 10 days after the first symptoms before all blisters have crusted over. This is when the person with chickenpox can return to day care, school, or work.
Chickenpox appears as a very itchy rash that spreads from the torso to the neck, face and limbs. Lasting seven to 10 days, the rash progresses from red bumps to fluid-filled blisters (vesicles) that drain and scab over. Vesicles may also appear in the mouth, on the scalp, around the eyes or on the genitals and can be very painful.
This cycle repeats itself in new areas of the body until finally, after about two weeks, all of the sores have healed. The disease is contagious until all the spots have dried up. Unfortunately, the virus is also contagious for at least one day before the rash breaks out.
Seek medical advice about chickenpox if:
You think your child has chickenpox. A doctor can confirm your diagnosis.
Chickenpox is accompanied by severe skin pain and the rash produces a greenish discharge and the surrounding skin becomes red, which are signs of a secondary bacterial skin infection.
Chickenpox is accompanied by a stiff neck, persistent sleepiness or lethargy as these are symptoms of a more serious illness such as meningitis or encephalitis. Get medical help immediately.
Your child is recovering from chickenpox and begins running a fever, vomiting, having convulsions or is drowsy. Get medical help immediately.
An adult family member gets chickenpox.
You are pregnant, have never had chickenpox and are exposed to the disease. Your unborn child may be at risk so seek medical advice without delay.
What are the treatments for chickenpox?
Chickenpox is extremely contagious. Keep your child at home until all of the blisters have burst and crusted over.
Most cases of chickenpox require little or no treatment beyond treating the symptoms.
The prescription antiviral drug aciclovir is effective for shortening the duration of chickenpox symptoms and may be recommended for certain people with chickenpox, such as pregnant women, those with a weakened immune system, and adults who seek medical advice within 24 hours of the rash appearing.
In addition, your doctor may recommend over-the-counter painkillers and an antihistamine to relieve pain, itching and swelling. Antibiotics are called for if a secondary bacterial skin infection arises or if the person with chickenpox develops bacterial pneumonia.
What to do
To prevent spreading the infection, keep children off nursery or school until all their spots have crusted over.
Chickenpox is infectious from one to two days before the rash starts, until all the blisters have crusted over (usually five to six days after the start of the rash).
If your child has chickenpox, try to keep them away from public areas to avoid contact with people who may not have had it, especially people who are at risk of serious problems, such as newborn babies, pregnant women and anyone with a weakened immune system (for example, people having cancer treatment or taking steroid tablets).
Read more about what you need to do to stop chickenpox spreading.
Chickenpox treatment
Chickenpox in children is considered a mild illness, but your child will probably feel pretty miserable and irritable while they have it.
Your child may have a fever for the first few days of the illness. The spots can be incredibly itchy.
There is no specific treatment for chickenpox, but there are pharmacy remedies that can alleviate symptoms. These include paracetamol to relieve fever, and calamine lotion and cooling gels to ease itching.
In most children, the blisters crust up and fall off naturally within one to two weeks.
Read more about chickenpox treatments.
When to see a doctor
For most children, chickenpox is a mild illness that gets better on its own.
However, some children can become more seriously ill with chickenpox and need to see a doctor.
Contact your GP straight away if your child develops any abnormal symptoms, such as:
if the blisters on their skin become infected
if your child has a pain in their chest or has difficulty breathing
Chickenpox in adults
Chickenpox may be a childhood illness, but adults can get it too. Chickenpox tends to be more severe in adults than children, and adults have a higher risk of developing complications.
Adults with chickenpox should stay off work until all the spots have crusted over. They should seek medical advice if they develop any abnormal symptoms, such as infected blisters.
Adults with chickenpox may benefit from taking antiviral medicine if treatment is started early in the course of the illness. Read more about antivirals in the treatment of chickenpox.
Who's at special risk?
Some children and adults are at special risk of serious problems if they catch chickenpox. They include:
pregnant women
newborn babies
people with a weakened immune system
These people should seek medical advice as soon as they are exposed to the chickenpox virus or they develop chickenpox symptoms.
They may need a blood test to check if they are protected from (immune to) chickenpox.
Read more about immunity testing and the diagnosis of chickenpox in people at special risk.
Chickenpox in pregnancy
Chickenpox occurs in approximately 3 in every 1,000 pregnancies. It can cause serious complications for both the pregnant woman and her baby. See complications of chickenpox for further information on what to do if you are exposed to chickenpox during pregnancy.
Chickenpox and shingles
Once you have had chickenpox, you usually develop antibodies to the infection and become immune to catching it again. However, the virus that causes chickenpox, the varicella-zoster virus, remains inactive (dormant) in your body's nerve tissues and can return later in life as an illness called shingles.
It's possible to catch chickenpox from someone with shingles, but not the other way around.
Read more about shingles.
Is there a vaccine against chickenpox?
There is a chickenpox vaccine, but it is not part of the routine childhood vaccination schedule. The vaccine is only offered to children and adults who are particularly vulnerable to chickenpox complications.
The recommended two doses of the vaccine is estimated to offer 98% protection from chickenpox in children and 75% protection in adolescents and adults.
So it may be possible to develop the infection after vaccination. Similarly, there is a chance that someone who has received the vaccine could develop chickenpox after coming in close contact with a person who has shingles.
Exams and Tests
Your health care provider can usually diagnose chickenpox by looking at the rash and asking questions about the person's medical history. Small blisters on the scalp usually confirm the diagnosis.
Laboratory tests can help confirm the diagnosis, if needed.
Outlook (Prognosis)
Usually, a person recovers without complications.
Once you have had chickenpox, the virus usually remains dormant or asleep in your body for your lifetime. About 1 in 10 adults will have shingles when the virus reemerges during a period of stress.
Possible Complications
Rarely, serious infections such as encephalitis have occurred. Other complications may include:
Reye's syndrome
Myocarditis
Pneumonia
Transient arthritis
Cerebellar ataxia may appear during the recovery phase or later. This involves a very unsteady walk.
Women who get chickenpox during pregnancy can pass the infection to the developing baby. Newborns are at risk for severe infection.
When to Contact a Medical Professional
Call your health care provider if you think that your child has chickenpox or if your child is over 12 months of age and has not been vaccinated against chickenpox.
Prevention
Because chickenpox is airborne and very contagious before the rash even appears, it is difficult to avoid.
A vaccine to prevent chickenpox is part of a child's routine immunization schedule. For information, see: Chickenpox vaccine
The vaccine usually prevents the chickenpox disease completely or makes the illness very mild.
Talk to your doctor if you think your child might be at high risk for complications and might have been exposed. Immediate preventive measures may be important. Giving the vaccine early after exposure may still reduce the severity of the disease.
Alternative Names
Varicella; Chicken pox
References
Myers MG, Seward JF, LaRussa PS. Varicella-zoster virus. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 250.