Carl R. Darnall Army Medical Center - Health Library

Chickenpox

(Varicella)

Definition

Chickenpox is a virus that spreads easily to others. It results in an itchy rash.

Chickenpox

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Causes  ^

A virus called varicella-zoster virus (VZV) causes this illness. It spreads through:

  • Breathing airborne droplets that have the VZV virus
  • Direct contact with fluid from a chickenpox rash

A pregnant mother can also pass it to her fetus.

Risk Factors  ^

The main risk factor is contact with someone with chickenpox. It is most common in children under 10 years of age. It is also more common in winter and spring.

Factors that may raise the chance of problems are:

  • No history of chickenpox
  • Conditions or medicines that lower your ability to fight infection, such as cancer, HIV infection, or an organ transplant
  • Maternal exposure during pregnancy

Symptoms  ^

Symptoms start about 10 to 21 days after contact. They are worse in adults than they are in children.

You may start by having:

  • Mild headache
  • Mild fever
  • Cough
  • Sore throat
  • Severe itch
  • Lack of hunger
  • Belly pain

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

  • Starts with small, flat, red spots:
    • Spots become raised and form a round, very itchy, fluid-filled blister
    • Blisters happen in clusters, with new ones forming over 5 to 6 days
  • Starts in patches on the skin above the waist, such as the scalp
  • May also appear on the eyelids, in the mouth, upper airway, voice box, or on the genitals
  • Crusts over by day 6 or 7 and goes away within 3 weeks

Diagnosis  ^

The doctor will ask about your symptoms and health history. A physical exam will be done. The doctor can often diagnose based on the rash.

Treatment  ^

Chickenpox is mild in most people. It will pass on its own. In most, it will last for 1 to 3 weeks. Home care can help ease discomfort.

Some may have serious problems from it.

To Reduce Itching

The rash can be very itchy. But scratching can harm the skin. It can also raise risk for infection. Itchiness can be reduced with:

  • Wet compresses
  • Over-the-counter anti-itch creams or lotions
  • Oral antihistamine medicine

Note: Do not use aspirin in children with a current or recent viral infection. Check with your doctor before giving your child aspirin.

High Risk Support

Some people have a higher risk of complications including:

  • Adolescents, adults, and people with weak immune systems
  • People with long term skin or lung diseases and those taking aspirin or steroids

Medicine may help shorten the infection. It may also reduce how severe the symptoms are. Medicines are:

  • Antiviral medicine
  • Varicella-zoster immune globulin—used for newborns and people with weak immune systems

Prevention  ^

Avoid being around anyone who has chickenpox.

There is a chickenpox vaccine. This can prevent illness even if you have been around someone who is sick. Vaccines may be given:

  • To children—as a combination MMRV
  • To adults—if they did not get one as child or have chickenpox
  • After exposure—in adults or children who have not had the vaccine; may help to decrease or prevent illness
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 Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T116084/Chickenpox. Updated June 19, 2017. Accessed July 16, 2018.

Gales SA, Sweet A, Beninger P, 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/index.html. Updated February 6, 2018. Accessed July 16, 2018.

Marin M, Meissner HC, Seward JF. Varicella prevention in the United States: a review of successes and challenges. Pediatrics. 2008;122(3):e744-e751.

A New Product (VariZIG) for Postexposure Prophylaxis of Varicalla Available under an Investigational New Drug Application Expanded Access Protocol. MMWR. 2006;55(8): 209-210.

Skull SA, Wang EE. Varicella vaccination: a critical review of the evidence. Arch Dis Child. 2001;85(2):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 November 22, 2016. Accessed July 16, 2018.

Vazquez M, LaRussa PS, Gershon AA, et al. Effectiveness over time of varicella vaccine. JAMA. 2004;291(7):851-855.

10/14/2008 DynaMed Plus Systematic Literature Surveillance. Available at:http://www.dynamed.com/topics/dmp~AN~T116084/Chickenpox: 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 June 2018 by James P. Cornell, MD  Last Updated: 7/16/2018