Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

Chickenpox

(Varicella)
by Rick Alan
Definition

Chickenpox is a viral infection. It is highly contagious. It creates a widespread itchy rash. In some, the infection can also cause serious complications. The infection is more dangerous for adults and newborns. It is also a danger for people with suppressed immune systems.

Causes

Chickenpox is caused by the varicella zoster virus (VZV). It spreads from person to person via:

  • Airborne droplets of moisture containing the VZV virus
  • Direct contact with fluid from a chickenpox rash

It is contagious 1-2 days before the rash erupts. It remains so until all of the blisters have crusted five days later. It is most contagious just after the rash has broken out.

A pregnant mother can transmit virus to fetus.

Risk Factors

Factors that increase your chance of getting chickenpox include:

  • Close contact with an infected person (unless you've been vaccinated or have already had chickenpox)
  • Immune deficient state (eg, leukemia , organ transplantation, high-dose steroid, HIV)
  • Age: less than three years old with peak incidence between 5-9 years old
  • Cancer
  • Pregnancy
  • Time of year (late winter, early spring)
Symptoms

Symptoms break out about 10-21 days after contact. They are more severe in adults than they are in children.

Initial symptoms include:

  • Cough
  • General feeling of malaise
  • Lack of appetite
  • Mild headache
  • Moderate fever
  • Severe itch
  • Some children complain of abdominal pain
  • Sore throat

The rash appears within 1-2 days after the first symptoms. The rash will:

  • At first consists of small, flat, red spots
    • Blisters develop in clusters, with new clusters forming over 5-6 days
    • Spots become raised and form a round, intensely itchy, fluid-filled blister
  • May also appear on the eyelids, in the mouth, upper airway, voice box, or on the genitals
  • Typically crusts over by day six or seven and disappears within three weeks
  • Usually develop into crops on the skin above the waist, including the scalp
Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. Diagnosis is usually made on the basis of age and the rash. Blood and lab tests to identify the virus are rarely needed.

Treatment

In most people, chickenpox is mild. It will naturally run its course. In these cases, treatment focuses on relieving the symptoms.

To Reduce Itching
  • Oral antihistamines (eg Benadryl )
  • Nonprescription anti-itch creams or lotions
  • Oatmeal baths
  • Wet compresses on the skin
  • Note : Aspirin is not recommended for children or teens with a current or recent viral infection. This is because of the risk of Reye's syndrome . Ask your doctor which other medicines are safe for your child.
Antibiotics

Antibiotics can not cure infections caused by a virus. They may be given if the rash becomes infected with bacteria.

Antiviral Medication

The course, severity and duration of the infection may be reduced by antiviral medications such as:

  • Acyclovir
  • Famciclovir
  • Valacyclovir

They are often used in:

  • Adolescents, adults, and individuals with compromised immune systems
  • Individuals with chronic skin or lung diseases and those taking aspirin or steroids
Special Needs

Varicella-zoster immune globulin is often given immediately after exposure. It is reserved for newborns and people with weak immune systems.

Prevention

Avoid contact with anyone who has chickenpox. This is very important if you have not been vaccinated against the infection.

Vaccination in Children

The varicella vaccine or a combination vaccine called MMRV (protects against measles , mumps , rubella , and varicella) is recommended for most children.

There is a “catch-up” schedule if your child has missed the routine injections.

Vaccination in Adults

Adults who have never received the varicella vaccine or have never had chickenpox should also be vaccinated.

Vaccination After Exposure

If you or your child has not been vaccinated but has been exposed to chickenpox, a vaccine given right away may help lessen the severity of the infection or prevent it.

Last reviewed: September 2011 by Lawrence Frisch, MD, MPH.

RESOURCES:
CANADIAN RESOURCES:
References:
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  • 10/14/2008 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Macartney K, McIntryre P. Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults. Cochrane Database Syst Rev. 2008;(3):CD001833.