Chicken Pox (Varicella Zoster)

There have been many cases of chicken pox recently in our area.
No-one can predict how ill a child with Chicken Pox will become.
It is mainly unvaccinated children and partially vaccinated who are affected, because they do not have antibodies or resistance against the virus that causes Chicken Pox.

Cause:
Chicken Pox is caused by a virus that is related to the Herpes group of viruses.

Spread :
This virus spreads via airborne droplet particles and direct contact.
Once all the blisters have formed scabs, the patient is not contagious anymore.

Incubation :
From the time of contact and infection it takes between 14-21 days to become symptomatic if one is not immune against the virus. With close house hold contacts the incubation period is usually the quickest . The infected person becomes contagious about 48 hours before symptoms appears.

Symptoms and signs:  
Symptoms can vary considerably, depending on age, immune competency and nutritional status.
Unborn and newborn babies of mothers with Chicken Pox can be severely affected.
Babies born with Chicken Pox have a 30 % mortality rate.
In general, the older an otherwise healthy child, the less severe the disease and less likely the risk of complications.
In adults however, it is often more severe with a bigger risk of complications.
Fever occurs in varying degrees when the rash appears and may persist for a few days, even after the rash has appeared.
A rash that itches and could look like insect bites appears on any part of the body surface in crops.  Small reds spots appears and are in different stages. Some spots may only be appearing while others may be bigger and even start blistering. Spots may keep appearing over a period of a few days.
The blisters are generally 3-5 mm in diameter and filled with a clear fluid.
Scabs form after the spots blistered and break open in the order of which they appeared and started blistering.
It often takes 5-7 days for all the spots to blister and to form scabs and crust.

Diagnosis:
A diagnosis of Chicken Pox is considered where there is a history of contact with a person with the disease in the previous 2 -3 weeks in a patient that is not fully vaccinated or has an compromised immune system.
Swabs to detect viral particles could be done.
Blood tests to show antibodies forming against the virus may also be done.
These laboratory tests are usually not necessary to confirm a diagnosis of Chicken Pox since it’s a clinical diagnosis in most cases.

Complications:
Although Chicken Pox is a common childhood illness, it’s not always predictable how severe the rash will be or whether there will be complications.
Complications could include unacceptable scarring causing cosmetic issues.
Some children might get blisters in their mouth and throat and may become dehydrated because of not eating and drinking.
Fever due to the infection could cause febrile convulsions in children that are susceptible to fever convulsions.
Necrotizing fasciitis is a serious complication with possible debilitating consequences and severe scarring.
Chicken Pox Pneumonia is a potentially fatal complication and more likely in teens and adults.
Encephalitis, an infection of the brain, may occur with symptoms of confusion , convulsions and reduced level of consciousness and coma.
Post Chicken Pox Aseptic Meningitis and inflammation of the small brain is also not uncommon.
Later in life the Chicken Pox virus can become reactivated in superficial sensory nerves causing Herpes Zoster (Shingles). If it affects the facial nerves it could involve the eye and result in blindness.
If a person who had Chicken Pox becomes ill with a disease that suppresses the immune system and/or receives treatment for such a disease , the dormant Chicken Pox virus in the body could become reactivated and cause severe disseminated disease.

Prevention:
Maintaining good health and nutrition is good to help one’s body fight of the disease and hopefully get it in a milder form, but it still leaves you with the risk of complications later in life.
Avoidance of people with Chicken Pox is totally impractical, because people could be infective before displaying typical symptoms and signs of Chicken Pox.
Vaccination is recommended for all immune competent children with the inactivated virus of Chicken Pox. Adults that never had the disease as a child should also be vaccinated.
This is an active form of immunization, because your immune system is presented with the inactivated virus antigens that simulates infection with the wild strain of the virus. The body then develops it’s own antibodies against the virus that will protect one in future when confronted by the real wild stain that may cause disease.
The vaccine available to us is called Varilrix and is generally administered from the age of one year.
It is important that a booster dose is given 6 weeks after the first to achieve the best possible immune response and protection.
In countries where everybody receives a vaccination early in life, only one dose is necessary with a booster only at 6 years of age again.
This is not currently part of the Extended Program of Vaccination in our country, due to the huge cost implications to our government.

Please read the package insert when your child is vaccinated.
The most frequent complication is that the person could develop a mild Chicken Pox rash.
It is important to note that the advantages of vaccination by far out weighs the very small risks of this vaccine,like all other vaccines.
Babies and immune compromised children with a very high risk of serious complications from the disease could be administered a passive form of immunization after exposure.
This is done by giving Varicella Zoster Immunoglobulin (VZIG).
VZIG is a concentrated form of human derived antibodies against Chicken Pox.

Treatment:
Fever can be treated with Paracetamol to keep the child comfortable and pain free.
It is important to avoid giving anti inflammatory medication like Ibuprofen, because it is suggested that it can worsen the course of the disease.
Never give aspirin to a child with Chicken Pox, it could cause Rye Syndrome, resulting in brain and liver failure.
For the itchy skin rash an oral antihistamine like Allergex is suggested. This will keep the child comfortable and prevent them from scratching the blisters that might become secondary infected with bacteria on the skin.
There are various topical applications to reduce the skin irritation caused by the rash and blisters.
Calamine lotion may be used or a spray called Poxclin.
As soon as the diagnosis is confirmed clinically, the antiviral medication Acyclovir should be started. It stops the replication of the virus and thus prevents progression of the disease process.
Most of the spots that have not blistered yet will not blister and few more new spots will appear once the antiviral medication has been started.
It is the blisters that form scabs that might continue to form the scars that could be disfiguring in some cases.
Starting early might also prevent some of the more serious complications of Chicken Pox that might occur.
It is seldom necessary to hospitalize children with Chicken Pox if it is uncomplicated.
When complications occur as mentioned admission to a hospital is required.
Immune compromised children and babies under 6 months of age may also be considered for admission to insure no complications occurs.

Conclusion :
Although unusual, mild Chicken Pox could be fatal in some cases.
Treatment is available and should always be considered .
Chicken Pox, with its complications, are preventable by simple vaccination and everybody should be vaccinated .

Dr Willem Smit Paediatrician

 

Leave a Reply

Your email address will not be published. Required fields are marked *