: Chickenpox and its Prevention in Children: An Update
What is chickenpox?
Chickenpox or varicella is a very contagious or easy to spread
infection caused by the varicella zoster virus.
This virus is spread form one person to another in one of two
By direct contact with the actual rash or
Through the air by coughing or sneezing, just like a cold
How common is chickenpox?
Varicella is a very common childhood infection. Most children
by the age of 9 will have had chickenpox. In Canada there are
about 350,000 cases of chickenpox each year.
What are the symptoms of chickenpox?
This varies from child to child. Some children develop such a
mild form of chickenpox that their parents do not even realize
that they have had it. However in the typical cases, the disease
starts with one or more of the following:
Within a day or so, the typical chickenpox rash develops, which
is a very characteristic one and usually easy to identify. The
rash begins as a red round or oval spot that develops a "blister-like"
center full of a yellowish fluid containing the varicella virus.
The rash which can be quite itchy, may occur anywhere on the body.
Some children develop very few blisters while others seem to have
their whole body covered.
When is chickenpox contagious?
A child developing chickenpox is considered to be contagious a
couple of days before the rash actually breaks out. This is why
the disease spreads so easily, as children are contagious before
the rash comes out and generally still attend school or daycare.
Once the rash appears, the child is contagious for about 3 - 5
days, or until all of the blisters have dried or crusted off.
Only when all the lesions are crusted can a child return to school
or day care.
Parents often wonder how long it takes to develop the illness
after being exposed to a child with chickenpox. This period known
as the "incubation period", ranges between 11 to 20 days, although
for most children it develops within 14 days. If a child does
not develop chicken pox after this period, then he or she has
not been infected this time.
What are the complications of chickenpox?
Fortunately most children do not suffer any serious consequences
from chickenpox infections. From a cost-to-society point of view,
chicken pox can be expensive and inconvenient. Children miss school,
parents have to miss work, causing inconvenience and a loss of
productivity all around. However, approximately 1 in 2000 children
may develop more serious complications, which account for 1900
children a year requiring hospitalization. These complications
Bacterial infection of the rash, and rarely "flesh eating disease"
Brain inflammation or encephalitis
Balance problems related to infection of a specific part of the
Death (very rare)
Who is particularly susceptible to chickenpox?
Varicella zoster infections are more serious or dangerous in the
following groups(high risk individuals):
Very young children
Adults or children with weak immune systems(such AIDS, or cancer)
People on medications that weaken their immune system(such as
What is the treatment of chickenpox?
There is no specific recommended treatment or medicine for normal
children who develop chickenpox.
The general approach to uncomplicated chicken pox infections include:
Calamine lotion application and soothing baths(oatmeal, baking
soda or cornstarch) to help relieve the itch
Cool compresses may also help
Making sure children have short nails so they don't scratch and
infect the rash(young babies may need mittens)
For temperature control Acetaminophen can be given as needed for
age and weight
ASA or Aspirin SHOULD NEVER BE GIVEN TO CHILDREN WITH CHICKENPOX
Making sure they are drinking well(and enough).
If a child is having difficulty eating because of chickenpox in
the mouth offer him/her cold fluids(avoid acid drinks like apple
or orange juice ) and a soft diet
For high risk individuals who either develop or are exposed to
varicella infection, there are certain anti-viral medications
and other treatments that may need to be given to protect their
weakened body. In many cases, this will require hospitalization.
When to seek medical attention?
You should see a doctor of your if:
Signs of infection around the blisters develop such as redness
There is a very high fever
The child vomits more than 3 times
The child is confused, difficult to waken or has trouble walking
You are worried that your child is not following the typical course
of chickenpox(say as compared to another child)
Can chickenpox be prevented by a vaccine?
Yes, now there is a vaccine that protects children from chickenpox.
Although chickenpox in most cases is not serious, the potential
for complications, have prompted the American Academy of Paediatrics
and the Canadian Paediatric Society to recommend the Varicella
vaccination for children between 12 and 18 months of age who have
not had chickenpox. They have also recommended a universal catch-up
vaccination program for older children who have not yet had chickenpox.
The vaccine has been proven to be 85% effective in preventing
the disease and almost 100% effective in preventing severe disease.
Obviously, this results in a decrease of potential complications.
As with all vaccines, safety is a concern. Having been administered
to 29 million people worldwide and studied in over 90,0000 children
and adults, the varicella vaccine is considered to be safe. Only
a few mild, temporary side-effects were reported including soreness,
tiredness, fussiness, fever, nausea and a bit of swelling where
the shot was given. Also, in a small percentage of people who
were vaccinated, a rash may develop over the body.
For children aged 12 month to 12 years, only one dose is needed.
For older children and adults two doses, 4 to 8 weeks apart are
Can chickenpox infection recur?
Technically no. However after a chickenpox infection, the varicella
virus remains in the body forever. The virus, for reasons not
clearly understood, lives "asleep" in the nerves. For a variety
of reasons, usually in older people or those with weakened immune
systems the virus appears on the skin again. However, this time
it only comes out in the area that specific nerve feeds, called
a dermatome. It looks like a patch of varicella blisters. This
is called Herpes Zoster(Zona) or shingles. People who have not
yet had chickenpox or have not had the varicella vaccination can
actually contract the virus and develop typical chickenpox infection
if they come into contact with someone who has shingles. People
who have had the disease or have been vaccinated will be protected
from the virus whether they come into contact with someone who
has either active typical chickenpox or shingles.
Are there any tests to prove that someone has had chickenpox?
Sometimes people do not remember if they have had chickenpox.
This may be especially important in persons who work with children.
There is blood test that can confirm whether or not a person has
been infected by chickenpox in the past. In many cases the test
is usually positive signifying that they have had a varicella
virus infection but it was so mild that they didn't realize they
MORE DR.PAUL VARICELLA(CHICKENPOX)LINKS:
Other Childhood Illnesses
The information provided in this site is
designed to be an educational aid only. It is not intended to
replace the advice and care of your child's physician, nor is
it intended to be used for medical diagnosis or treatment. If
you suspect that your child has a medical condition, always
consult a physician.
© Autograph Communications Inc.,
All rights reserved