Chickenpox

(Varicella)

Definition

Definition

Chickenpox is a virus that spreads easily to others. It creates an itchy rash. The infection can also cause serious complications in some people.

Chickenpox

Copyright © Nucleus Medical Media, Inc.

Causes

Causes

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

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

A pregnant mother can transmit the virus to a fetus.

Risk Factors

Risk Factors

Chickenpox is more common in children under 10 years old. Other factors that may increase your chance of chickenpox include:

  • Close contact with an infected person, unless you have been vaccinated or have already had chickenpox
  • Conditions or medications that suppress your immune system, such as cancer, HIV infection, an organ transplant, or high-dose steroid use
  • Pregnancy
  • Time of year—late winter, early spring

Symptoms

Symptoms

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

Initial symptoms include:

  • Mild headache
  • Moderate fever
  • Cough
  • Sore throat
  • Severe itch
  • Lack of appetite
  • General feeling of discomfort
  • Abdominal pain

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

  • Begins with small, flat, red spots:

    • Spots become raised and form a round, intensely itchy, fluid-filled blister
    • Blisters develop in clusters, with new clusters forming over 5-6 days
  • Usually develops into patches on the skin above the waist, including the scalp
  • May also appear on the eyelids, in the mouth, upper airway, voice box, or on the genitals
  • Typically crusts over by day 6 or 7 and disappears within 3 weeks

Diagnosis

Diagnosis

You will be asked your symptoms and medical history. A physical exam will be done. Diagnosis is usually based on the rash and your age. Blood and lab tests to identify the virus are rarely needed.

Treatment

Treatment

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

To Reduce Itching

It may be difficult to avoid scratching. Itchiness can be reduced with:

  • Wet compresses
  • Over-the-counter anti-itch creams or lotions
  • Oatmeal baths
  • Oral antihistamine medication

Note: Aspirin is not recommended for children with a current or recent viral infection. Check with your doctor before giving your child aspirin.

Antibiotics

Antibiotics cannot cure infections caused by a virus. However, 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.

They are often used in:

  • Adolescents, adults, and individuals with weak 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

Prevention

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

Vaccination in Children

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

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

Vaccination in Adults

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

Vaccination After Exposure

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

RESOURCES:

Centers for Disease Control and Prevention http://www.cdc.gov

Family Doctor—American Academy of Family Physicians http://familydoctor.org

CANADIAN RESOURCES:

About Kids Health—The Hospital for Sick Children http://www.aboutkidshealth.ca

College of Family Physicians of Canada http://www.cfpc.ca

References:

Chickenpox. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated August 14, 2014. Accessed May 29, 2015.

Gales SA, Sweet A, et al. The safety profile of varicella vaccine: a 10-year review. J Infect Dis. 2008;197(Suppl2):S165-9).

Immunization schedules. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/vaccines/schedules
Updated January 26, 2015. Accessed May 29, 2015.

Marin M, Meissner HC, et al. Varicella prevention in the United States: a review of successes and challenges. Pediatrics. 2008;122: e744-51.

A New Product (VariZIG) for Postexposure Prophylaxis of Varicalla Available under an Investigational New Drug Application Expanded Access Protocol. MMWR. 2006;55: 209-210.

Skull SA, Wang EE. Varicella vaccination: a critical review of the evidence. Arch Dis Child. 2001;85:83-90.

Varicella (chickenpox) vaccination. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/vaccines/vpd-vac/varicella/default.htm
Updated April 5, 2012. Accessed May 29, 2015.

Vazquez M, LaRussa PS, et al. Effectiveness over time of varicella vaccine. JAMA. 2004;291:851-855.

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

Last reviewed May 2015 by Michael Woods, MD
Last Updated: 5/29/2015

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