Disease Topics:Chickenpox

Chickenpox: Picture, symptoms, treatment and prevention


What is chickenpox?

Chickenpox (varicella), a viral illness characterised by a very itchy red rash, is one of the most common infectious diseases of childhood. It is usually mild in childrenbut there is a risk of serious complications, such as bacterial pneumonia.

Picture of Varicella Chickenpox

People who have had chickenpox almost always develop lifetime immunity (meaning you are extremely unlikely to get it again). However, the virus remains dormant in the body and it can reactivate later in life and cause shingles.

What causes chickenpox?

Chickenpox is caused by the herpes varicella-zoster virus. It is spread by droplets from a sneeze or cough, or by contact with the clothing, bed linens or oozingblisters of an infected person. The onset of symptoms is 10 to 21 days after exposure. The disease is most contagious a day or two before the rash appears and until the rash is completely dry and scabbed over.

What are the symptoms of chickenpox?

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 anantihistamine to relieve pain, itching and swellingAntibiotics are called for if a secondary bacterial skin infection arises or if the person with chickenpox develops bacterial pneumonia.



The chickenpox vaccine protects against infection in 80 to 90 percent of those who are vaccinated. People who do not develop full protection from the vaccine may develop chickenpox after exposure. However, their illness is usually mild and causes a less severe rash and often no fever.

Vaccination in children — In the United States, the varicella vaccine is recommended for all children at 12 through 15 months of age. A second dose is recommended at 4 to 6 years of age. The second dose may be administered earlier than age 4 years (for example, during a varicella outbreak); for such children <13 years, the two doses should be given at least three months apart. The vaccine may be given in a formulation that combines vaccines for measles, mumps, rubella, and varicella (MMRV, ProQuad). The varicella vaccine is not needed if a child is infected with chickenpox before being vaccinated. (See"Vaccination for the prevention of primary varicella infection (chickenpox)".)

Vaccination in adults — Most adults have not been given the varicella vaccine because they already had the infection in childhood, prior to the availability of vaccine in 1995. People who had chickenpox in the past are immune to varicella infection.

In contrast, adults who do not have immunity to chickenpox can benefit from being vaccinated. In fact, experts recommend varicella vaccination for adults without immunity, especially those who are at risk of exposure to chickenpox and those who are in contact with people who are at risk for severe chickenpox infection. This includes:

?Healthcare workers

?Those who are in close contact with people with a compromised immune system (this includes transplant recipients and people with HIV)

?Teachers of young children

?Daycare employees

?Susceptible young adults in colleges, military bases, or correctional facilities

?International travelers

?Women of childbearing age; however, women who are pregnant or plan to become pregnant soon should not receive the varicella vaccine.


If you are at risk for chickenpox but are unsure whether you have had the infection, you can have a blood test to check for immunity to varicella.

To be fully vaccinated, adults and children 13 years and older need two doses of the varicella vaccine, given at least four weeks apart.

Chickenpox vaccine precautions — The varicella vaccine contains a live virus, so it is not recommended for people with a compromised immune system or moderate to severe illness. In addition, the vaccine should not be given to people who have a severe allergy to neomycin or gelatin. (See "Allergic reactions to vaccines".)

Chickenpox vaccine side effects — The most common side effects of the varicella vaccine are redness or soreness at the injection site and a mild rash (usually about five spots). Contrary to popular belief, having the varicella vaccinedoes not increase the risk of developing shingles compared with natural infection.